diff --git a/M02_MasterTemplete/M02_MasterTemplete_Api_Fetch.ts b/M02_MasterTemplete/M02_MasterTemplete_Api_Fetch.ts
index 52499b89..3a3d6919 100644
--- a/M02_MasterTemplete/M02_MasterTemplete_Api_Fetch.ts
+++ b/M02_MasterTemplete/M02_MasterTemplete_Api_Fetch.ts
@@ -403,3 +403,39 @@ export const saveInputLinks = (
   줄: InputLine[],
 ): Promise<{ 판: string }> =>
   call(itemPath(layer, key, "input-links"), { method: "PUT", body: JSON.stringify({ 판, 줄 }) });
+
+/* --- 항목 나무(PLAN 26-1 · 26-3a) — 폴더 경로 깊이 자유 · 고침은 층 쓰기 권한 --- */
+export interface TreeItem {
+  key: string;
+  열: string;
+  경로: string[];
+  이름: string;
+  단위?: string | null;
+  일위대가?: string | null;
+}
+export interface TreeNote {
+  op: string;
+  경로?: string[];
+  열?: string;
+  지운항목?: string[];
+}
+export interface TreeView {
+  판: string;
+  폴더: string[][];
+  items: TreeItem[];
+  알림?: TreeNote;
+}
+export interface TreeEdit {
+  op: "add-folder" | "add-item" | "rename" | "move" | "delete";
+  경로?: string[];
+  이름?: string;
+  새경로?: string[];
+  키?: string;
+  단위?: string;
+}
+
+export const fetchTree = (layer: Layer): Promise<TreeView> => call(`/layers/${layer}/tree`);
+
+/** 판이 다르면 409(`StaleError`) — 부르는 쪽이 다시 읽음 */
+export const editTree = (layer: Layer, edit: TreeEdit, 판: string): Promise<TreeView> =>
+  call(`/layers/${layer}/tree`, { method: "POST", body: JSON.stringify({ ...edit, 판 }) });
diff --git a/M02_MasterTemplete/M02_MasterTemplete_TreePanel.css b/M02_MasterTemplete/M02_MasterTemplete_TreePanel.css
new file mode 100644
index 00000000..7efac906
--- /dev/null
+++ b/M02_MasterTemplete/M02_MasterTemplete_TreePanel.css
@@ -0,0 +1,40 @@
+/* 관리 화면 항목 나무 — 줄 모양은 공용 ui-tree · ui-sidebar-row */
+.m02-tree {
+  padding-top: var(--spacing-8);
+  display: flex;
+  flex-direction: column;
+  gap: var(--spacing-8);
+  min-width: 0;
+}
+
+.m02-tree__body {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  max-height: 55vh;
+  min-height: 4rem;
+  overflow: auto;
+  outline: none;
+}
+
+.m02-tree__body .ui-tree__row {
+  min-width: 0;
+  overflow-wrap: anywhere;
+}
+
+.m02-tree__hint {
+  margin: 0;
+  padding: var(--spacing-8);
+  color: var(--color-text-muted);
+  font-size: var(--text-body-sm);
+}
+
+.m02-treedlg {
+  width: min(24rem, calc(100vw - 2 * var(--spacing-16)));
+}
+
+.m02-treedlg .ui-modal__body {
+  display: flex;
+  flex-direction: column;
+  gap: var(--spacing-12);
+}
diff --git a/M02_MasterTemplete/M02_MasterTemplete_TreePanel.ts b/M02_MasterTemplete/M02_MasterTemplete_TreePanel.ts
new file mode 100644
index 00000000..80ece6bb
--- /dev/null
+++ b/M02_MasterTemplete/M02_MasterTemplete_TreePanel.ts
@@ -0,0 +1,372 @@
+/* =============================================================================
+ * M02_MasterTemplete_TreePanel.ts
+ * 관리 화면(마스터 · 회사 · 개인 공용) 좌측 「항목 나무」 — 폴더 → … → 항목(깊이 자유) · 찾기.
+ * 항목을 누르면 표에서 그 열이 골라짐(카드 넷은 표가 엶) · 표에서 열을 고르면 `select` 로 나무도 그 항목.
+ * 오른쪽 클릭 · 키보드(F2 · Delete)로 폴더 · 항목 더하기 · 이름 바꾸기 · 옮기기 · 지우기 —
+ * `POST /api/m02/layers/{층}/tree`(PLAN 26-1). 읽기만 층은 메뉴 · 키 없음. 나무 자료는 `_Model`.
+ * ========================================================================== */
+
+import "./M02_MasterTemplete_TreePanel.css";
+import { createInputField, el, showConfirmDialog, showToast } from "@ui/ui_template_elements";
+import { t as L } from "@ui/ui_template_locale";
+import {
+  createTreeRow,
+  openTreeMenu,
+  renderTree,
+  type MakeRow,
+  type TreeMenuItem,
+  type TreeNode,
+} from "@ui/ui_template_tree";
+import {
+  StaleError,
+  editTree,
+  fetchTree,
+  type Layer,
+  type TreeEdit,
+  type TreeItem,
+  type TreeNote,
+  type TreeView,
+} from "./M02_MasterTemplete_Api_Fetch";
+import { askFolder, askText } from "./M02_MasterTemplete_TreePanel_Dialogs";
+import {
+  ancestorsOf,
+  buildFolders,
+  countItems,
+  folderIdOf,
+  folderOf,
+  isUnder,
+  itemIdOf,
+  leafName,
+  listFolders,
+  samePath,
+  type FolderNode,
+} from "./M02_MasterTemplete_TreePanel_Model";
+
+export interface TreePanelOptions {
+  layer: Layer;
+  /** 이 층을 고칠 수 있나 — 아니면 메뉴 · 키 없음 */
+  canEdit: boolean;
+  /** 항목을 누름 — 표에서 그 열을 고름 */
+  onPick: (item: TreeItem) => void;
+  /** 고치기 전에 저장 안 한 표 고침을 처리 — 취소면 false · 저장했으면 "changed" */
+  settle: () => Promise<false | "clean" | "changed">;
+  /** 나무가 바뀜 — 표를 다시 읽고 그 열(`colId`)을 고름 */
+  onChanged: (colId: string | null) => Promise<void>;
+}
+
+export interface TreePanelHandle {
+  root: HTMLElement;
+  refresh: () => Promise<void>;
+  /** 표에서 고른 열을 나무에 표시(null = 지움) */
+  select: (colId: string | null) => void;
+}
+
+type Target = { kind: "folder"; path: string[] } | { kind: "item"; item: TreeItem };
+
+const why = (error: unknown): string => (error instanceof Error ? error.message : "");
+const hint = (text: string): HTMLElement => el("p", { className: "m02-tree__hint", text });
+
+export function createTreePanel(opt: TreePanelOptions): TreePanelHandle {
+  const layerLabel = L(
+    opt.layer === "company"
+      ? "M02_PickerCompany"
+      : opt.layer === "personal"
+        ? "M02_PickerPersonal"
+        : "M02_PickerSystem",
+  );
+  let view: TreeView | null = null;
+  let text = "";
+  let activeCol: string | null = null;
+  let seq = 0;
+  let busy = false;
+  const open = new Set<string>([folderIdOf([])]);
+  const targets = new Map<string, Target>();
+
+  const search = createInputField({ placeholder: L("M02_TreeSearch"), compact: true });
+  const body = el("div", { className: "m02-tree__body", attrs: { tabindex: "-1" } });
+  const root = el("div", { className: "m02-tree", children: [search.root, body] });
+
+  /* --- 그리기 --- */
+  const menuOf = (target: Target): TreeMenuItem[] => {
+    const isTop = target.kind === "folder" && !target.path.length;
+    return [
+      ...(target.kind === "folder"
+        ? [
+            { label: L("M02_TreeAddFolder"), run: () => void addFolder(target.path) },
+            { label: L("M02_TreeAddItem"), run: () => void addItem(target.path) },
+          ]
+        : []),
+      ...(isTop
+        ? []
+        : [
+            { label: L("M02_TreeRename"), run: () => void rename(target) },
+            { label: L("M02_TreeMove"), run: () => void move(target) },
+            { label: L("M02_Delete"), run: () => void remove(target) },
+          ]),
+    ];
+  };
+
+  function node(target: Target, base: Omit<TreeNode, "id" | "menu">, id: string): TreeNode {
+    targets.set(id, target);
+    return { ...base, id, ...(opt.canEdit ? { menu: () => menuOf(target) } : {}) };
+  }
+
+  function folderNode(folder: FolderNode, searching: boolean): TreeNode {
+    const id = folderIdOf(folder.path);
+    const kids = [
+      ...folder.folders.map((one) => folderNode(one, searching)),
+      ...folder.items.map((item) =>
+        node(
+          { kind: "item", item },
+          {
+            label: leafName(item),
+            count: null,
+            tip: `${item.이름} · ${item.key}`,
+            run: () => opt.onPick(item),
+          },
+          itemIdOf(item),
+        ),
+      ),
+    ];
+    return node(
+      { kind: "folder", path: folder.path },
+      {
+        label: folder.path.length ? folder.path[folder.path.length - 1] : layerLabel,
+        count: countItems(folder),
+        children: kids,
+        open: searching || open.has(id),
+        run: () => void (open.has(id) ? open.delete(id) : open.add(id)),
+      },
+      id,
+    );
+  }
+
+  const make: MakeRow = (one, caret, depth, onClick) => {
+    const button = createTreeRow(one, caret, depth, onClick);
+    button.dataset.node = one.id;
+    button.classList.toggle("is-active", !!activeCol && one.id === `i|${activeCol}`);
+    return button;
+  };
+
+  function paint(): void {
+    const focused = (document.activeElement as HTMLElement | null)?.dataset?.node;
+    targets.clear();
+    if (!view) return body.replaceChildren(hint(L("M02_PickerLoading")));
+    const searching = text.trim() !== "";
+    const tree = buildFolders(view, text);
+    const none = countItems(tree) === 0 && (searching || !tree.folders.length);
+    body.replaceChildren(
+      ...renderTree([folderNode(tree, searching)], make),
+      ...(none
+        ? [
+            hint(
+              L(searching ? "M02_TreeNoHit" : opt.canEdit ? "M02_TreeEmptyEdit" : "M02_TreeEmpty"),
+            ),
+          ]
+        : []),
+    );
+    if (focused) rowOf(focused)?.focus({ preventScroll: true });
+  }
+
+  const rowOf = (id: string): HTMLElement | null =>
+    [...body.querySelectorAll<HTMLElement>("[data-node]")].find((b) => b.dataset.node === id) ??
+    null;
+
+  async function refresh(): Promise<void> {
+    const mine = ++seq;
+    try {
+      const got = await fetchTree(opt.layer);
+      if (mine !== seq) return;
+      view = got;
+    } catch (error) {
+      if (mine !== seq) return;
+      view = null;
+      body.replaceChildren(hint(L("M02_PickerLoadFailed").replace("{value}", why(error))));
+      return;
+    }
+    paint();
+  }
+
+  function select(colId: string | null): void {
+    activeCol = colId;
+    const need =
+      view && colId ? ancestorsOf(view, colId).filter((p) => !open.has(folderIdOf(p))) : [];
+    if (need.length) {
+      need.forEach((p) => open.add(folderIdOf(p)));
+      paint();
+    } else {
+      body
+        .querySelectorAll<HTMLElement>("[data-node]")
+        .forEach((b) =>
+          b.classList.toggle("is-active", !!colId && b.dataset.node === `i|${colId}`),
+        );
+    }
+    if (colId) rowOf(`i|${colId}`)?.scrollIntoView({ block: "nearest" });
+  }
+
+  /* --- 고치기 --- */
+  /** 저장 안 한 표 고침 처리 → (바뀌었으면 나무 다시 읽음) → 참이면 계속 */
+  async function ready(): Promise<boolean> {
+    const settled = await opt.settle();
+    if (!settled) return false;
+    if (settled === "changed") await refresh();
+    return true;
+  }
+
+  async function edit(body_: TreeEdit, keepCol: string | null = activeCol): Promise<void> {
+    if (!view || busy) return;
+    busy = true;
+    try {
+      const got = await editTree(opt.layer, body_, view.판);
+      view = got;
+      const note: TreeNote | undefined = got.알림;
+      // 새 항목은 그 열을 고름 · 지운 항목이면 고름 풀림 · 나머지는 지금 고른 열 그대로
+      const gone = note?.지운항목 ?? [];
+      const col = note?.열 ?? (keepCol && !gone.includes(keepCol) ? keepCol : null);
+      activeCol = col;
+      const parent = note?.경로 ? note.경로.slice(0, -1) : [];
+      parent.forEach((_, i) => open.add(folderIdOf(parent.slice(0, i + 1))));
+      if (note?.op === "add-folder" || note?.op === "rename" || note?.op === "move") {
+        if (note.경로) open.add(folderIdOf(note.경로));
+      }
+      paint();
+      showToast(L("M02_TreeDone"), "success");
+      await opt.onChanged(col);
+    } catch (error) {
+      if (error instanceof StaleError) {
+        await refresh();
+        showToast(L("M02_TreeStale"), "error");
+      } else {
+        showToast(L("M02_ActionFailed").replace("{value}", why(error)), "error");
+      }
+    } finally {
+      busy = false;
+    }
+  }
+
+  const nameOf = (target: Target): string =>
+    target.kind === "item" ? leafName(target.item) : target.path[target.path.length - 1];
+
+  async function addFolder(parent: string[]): Promise<void> {
+    if (!(await ready())) return;
+    const got = await askText(L("M02_TreeAddFolder"), [
+      { key: "name", label: L("M02_TreeFolderName") },
+    ]);
+    if (got) await edit({ op: "add-folder", 경로: parent, 이름: got.name });
+  }
+
+  async function addItem(parent: string[]): Promise<void> {
+    if (!(await ready())) return;
+    const got = await askText(L("M02_TreeAddItem"), [
+      { key: "name", label: L("M02_TreeItemName") },
+      { key: "unit", label: L("M02_TreeUnit"), optional: true },
+    ]);
+    if (got) {
+      await edit({
+        op: "add-item",
+        경로: parent,
+        이름: got.name,
+        ...(got.unit ? { 단위: got.unit } : {}),
+      });
+    }
+  }
+
+  async function rename(target: Target): Promise<void> {
+    if (!(await ready())) return;
+    const got = await askText(L("M02_TreeRename"), [
+      {
+        key: "name",
+        label: L(target.kind === "item" ? "M02_TreeItemName" : "M02_TreeFolderName"),
+        value: nameOf(target),
+      },
+    ]);
+    if (!got || got.name === nameOf(target)) return;
+    await edit(
+      target.kind === "item"
+        ? { op: "rename", 경로: folderOf(target.item), 키: target.item.key, 이름: got.name }
+        : { op: "rename", 경로: target.path, 이름: got.name },
+    );
+  }
+
+  async function move(target: Target): Promise<void> {
+    if (!(await ready()) || !view) return;
+    const from = target.kind === "item" ? folderOf(target.item) : target.path.slice(0, -1);
+    const to = await askFolder(
+      L("M02_TreeMove"),
+      listFolders(buildFolders(view)),
+      (path) => target.kind === "folder" && isUnder(path, target.path),
+      from,
+    );
+    if (!to || samePath(to, from)) return;
+    await edit(
+      target.kind === "item"
+        ? { op: "move", 경로: from, 키: target.item.key, 새경로: to }
+        : { op: "move", 경로: target.path, 새경로: to },
+    );
+  }
+
+  async function remove(target: Target): Promise<void> {
+    if (!(await ready()) || !view) return;
+    const folder =
+      target.kind === "folder" ? findFolder(buildFolders(view), target.path) : undefined;
+    const message =
+      target.kind === "item"
+        ? L("M02_TreeDeleteItem").replace("{value}", leafName(target.item))
+        : L("M02_TreeDeleteFolder")
+            .replace("{value}", nameOf(target))
+            .replace("{n}", String(folder ? countItems(folder) : 0));
+    if (!(await showConfirmDialog(message, L("M02_Delete")))) return;
+    await edit(
+      target.kind === "item"
+        ? { op: "delete", 경로: folderOf(target.item), 키: target.item.key }
+        : { op: "delete", 경로: target.path },
+    );
+  }
+
+  const findFolder = (from: FolderNode, path: string[]): FolderNode | undefined =>
+    samePath(from.path, path)
+      ? from
+      : from.folders.map((one) => findFolder(one, path)).find(Boolean);
+
+  /* --- 이음 --- */
+  search.input.addEventListener("input", () => {
+    text = search.input.value;
+    paint();
+  });
+
+  // 빈 자리 오른쪽 클릭 = 맨 위 메뉴(폴더 · 항목 더하기)
+  body.addEventListener("contextmenu", (event) => {
+    if (!opt.canEdit || (event.target as HTMLElement).closest("[data-node]")) return;
+    event.preventDefault();
+    openTreeMenu(event, menuOf({ kind: "folder", path: [] }).slice(0, 2));
+  });
+
+  body.addEventListener("keydown", (event) => {
+    const row = (event.target as HTMLElement).closest<HTMLElement>("[data-node]");
+    if (!row) return;
+    const rows = [...body.querySelectorAll<HTMLElement>("[data-node]")].filter(
+      (b) => !b.closest("[hidden]"),
+    );
+    const at = rows.indexOf(row);
+    const caret = row.querySelector(".ui-tree__caret")?.textContent;
+    const target = targets.get(row.dataset.node ?? "");
+    if (event.key === "ArrowDown" || event.key === "ArrowUp") {
+      event.preventDefault();
+      rows[at + (event.key === "ArrowDown" ? 1 : -1)]?.focus();
+    } else if (
+      (event.key === "ArrowRight" && caret === "▸") ||
+      (event.key === "ArrowLeft" && caret === "▾")
+    ) {
+      event.preventDefault();
+      row.click();
+    } else if (opt.canEdit && target && event.key === "F2") {
+      event.preventDefault();
+      if (!(target.kind === "folder" && !target.path.length)) void rename(target);
+    } else if (opt.canEdit && target && event.key === "Delete") {
+      event.preventDefault();
+      if (!(target.kind === "folder" && !target.path.length)) void remove(target);
+    }
+  });
+
+  return { root, refresh, select };
+}
diff --git a/M02_MasterTemplete/M02_MasterTemplete_TreePanel_Dialogs.ts b/M02_MasterTemplete/M02_MasterTemplete_TreePanel_Dialogs.ts
new file mode 100644
index 00000000..962b31c4
--- /dev/null
+++ b/M02_MasterTemplete/M02_MasterTemplete_TreePanel_Dialogs.ts
@@ -0,0 +1,142 @@
+/* =============================================================================
+ * M02_MasterTemplete_TreePanel_Dialogs.ts
+ * 항목 나무 오른쪽 클릭 메뉴가 띄우는 작은 창 — 글 받기 · 옮길 폴더 고르기 · 저장/버림 물음.
+ * 모두 약속(Promise)으로 답함 — 닫기 · Esc · 바깥 누르기 = 취소(null / "cancel").
+ * ========================================================================== */
+
+import {
+  createButton,
+  createInputField,
+  createSelectField,
+  el,
+  showToast,
+} from "@ui/ui_template_elements";
+import { t as L } from "@ui/ui_template_locale";
+import { openModal } from "@ui/ui_template_modal";
+
+export interface TextField {
+  key: string;
+  label: string;
+  value?: string;
+  /** 비워도 됨(항목 단위) */
+  optional?: boolean;
+}
+
+/** 글 칸 하나 이상을 받음 — 확인이면 칸 이름 → 글(앞뒤 공백 뺌) */
+export function askText(
+  title: string,
+  fields: TextField[],
+  okLabel = L("M02_TreeOk"),
+): Promise<Record<string, string> | null> {
+  return new Promise((resolve) => {
+    let done = false;
+    const finish = (value: Record<string, string> | null): void => {
+      if (done) return;
+      done = true;
+      resolve(value);
+    };
+    openModal({
+      title,
+      closeLabel: L("M02_Close"),
+      dialogClass: "m02-modal m02-treedlg",
+      beforeClose: () => (finish(null), true),
+      mount: (body, close) => {
+        const inputs = fields.map((f) => ({
+          f,
+          field: createInputField({ label: f.label, value: f.value }),
+        }));
+        const ok = createButton({ label: okLabel, variant: "filled" });
+        const submit = (): void => {
+          const out: Record<string, string> = {};
+          for (const { f, field } of inputs) {
+            out[f.key] = field.input.value.trim();
+            if (!out[f.key] && !f.optional) return showToast(L("M02_NameNeeded"), "error");
+          }
+          finish(out);
+          close();
+        };
+        ok.addEventListener("click", submit);
+        for (const { field } of inputs) {
+          field.input.addEventListener("keydown", (event) => {
+            if (event.key === "Enter" && !event.isComposing) submit();
+          });
+        }
+        body.append(...inputs.map(({ field }) => field.root), ok);
+        inputs[0]?.field.input.select();
+      },
+    });
+  });
+}
+
+/** 옮길 폴더 고르기 — `folders` 에서 `blocked` 인 것은 뺌 · 맨 위(폴더 밖)는 늘 있음 */
+export function askFolder(
+  title: string,
+  folders: string[][],
+  blocked: (path: string[]) => boolean,
+  current: string[],
+): Promise<string[] | null> {
+  return new Promise((resolve) => {
+    let done = false;
+    const finish = (value: string[] | null): void => {
+      if (done) return;
+      done = true;
+      resolve(value);
+    };
+    const choices = [[], ...folders.filter((path) => !blocked(path))];
+    openModal({
+      title,
+      closeLabel: L("M02_Close"),
+      dialogClass: "m02-modal m02-treedlg",
+      beforeClose: () => (finish(null), true),
+      mount: (body, close) => {
+        const field = createSelectField({
+          label: L("M02_TreeMoveTo"),
+          options: choices.map((path, i) => ({
+            value: String(i),
+            text: path.length ? path.join(" / ") : L("M02_TreeTop"),
+          })),
+          value: String(choices.findIndex((path) => path.join("|") === current.join("|"))),
+        });
+        const ok = createButton({ label: L("M02_TreeOk"), variant: "filled" });
+        ok.addEventListener("click", () => {
+          finish(choices[Number(field.select.value)] ?? []);
+          close();
+        });
+        body.append(field.root, ok);
+      },
+    });
+  });
+}
+
+export type Settle = "save" | "discard" | "cancel";
+
+/** 저장 안 한 표 고침 — 저장하고 계속 · 버리고 계속 · 취소 */
+export function askSettle(): Promise<Settle> {
+  return new Promise((resolve) => {
+    let done = false;
+    const finish = (value: Settle): void => {
+      if (done) return;
+      done = true;
+      resolve(value);
+    };
+    openModal({
+      title: L("M02_TreeUnsaved"),
+      closeLabel: L("M02_TreeCancel"),
+      dialogClass: "m02-modal m02-treedlg",
+      beforeClose: () => (finish("cancel"), true),
+      mount: (body, close) => {
+        const choose = (value: Settle) => () => {
+          finish(value);
+          close();
+        };
+        const save = createButton({ label: L("M02_TreeSaveGo"), variant: "filled" });
+        const discard = createButton({ label: L("M02_TreeDiscardGo"), variant: "danger" });
+        const cancel = createButton({ label: L("M02_TreeCancel"), variant: "ghost" });
+        save.addEventListener("click", choose("save"));
+        discard.addEventListener("click", choose("discard"));
+        cancel.addEventListener("click", choose("cancel"));
+        body.append(el("div", { className: "m02-side__row", children: [save, discard, cancel] }));
+      },
+    });
+  });
+}
diff --git a/M02_MasterTemplete/M02_MasterTemplete_TreePanel_Model.ts b/M02_MasterTemplete/M02_MasterTemplete_TreePanel_Model.ts
new file mode 100644
index 00000000..4643cf08
--- /dev/null
+++ b/M02_MasterTemplete/M02_MasterTemplete_TreePanel_Model.ts
@@ -0,0 +1,67 @@
+/* =============================================================================
+ * M02_MasterTemplete_TreePanel_Model.ts
+ * 관리 화면 항목 나무의 자료 쪽(화면 없음) — 서버 나무(`폴더` + `items`)를 폴더 나무로 · 찾기 ·
+ * 폴더 목록. 항목 경로는 폴더 이름 배열 + 마지막 마디가 항목 이름(PLAN 26-1 · 깊이 자유).
+ * ========================================================================== */
+
+import type { TreeItem, TreeView } from "./M02_MasterTemplete_Api_Fetch";
+
+export interface FolderNode {
+  /** 이 폴더까지의 경로 — 맨 위 = 빈 배열 */
+  path: string[];
+  folders: FolderNode[];
+  items: TreeItem[];
+}
+
+export const samePath = (a: string[], b: string[]): boolean =>
+  a.length === b.length && a.every((part, i) => part === b[i]);
+
+/** `path` 가 `folder` 와 같거나 그 안인가 */
+export const isUnder = (path: string[], folder: string[]): boolean =>
+  folder.length <= path.length && folder.every((part, i) => part === path[i]);
+
+export const folderIdOf = (path: string[]): string => `f|${path.join("|")}`;
+export const itemIdOf = (item: TreeItem): string => `i|${item.열}`;
+export const leafName = (item: TreeItem): string => item.경로[item.경로.length - 1] ?? item.이름;
+export const folderOf = (item: TreeItem): string[] => item.경로.slice(0, -1);
+
+/** 찾기 — 경로 · 키 · 일위대가 키에 모든 낱말이 들어 있는 항목(빈 글이면 전부) */
+export function matches(item: TreeItem, text: string): boolean {
+  const words = text.trim().toLowerCase().split(/\s+/).filter(Boolean);
+  const hay = [...item.경로, item.key, item.일위대가 ?? ""].join(" ").toLowerCase();
+  return words.every((word) => hay.includes(word));
+}
+
+/** 폴더 나무 — 찾는 글이 있으면 맞는 항목과 그 위 폴더만 · 없으면 빈 폴더까지 전부 */
+export function buildFolders(view: TreeView, text = ""): FolderNode {
+  const searching = text.trim() !== "";
+  const root: FolderNode = { path: [], folders: [], items: [] };
+  const at = (path: string[]): FolderNode =>
+    path.reduce((node, name, i) => {
+      let next = node.folders.find((f) => f.path[i] === name);
+      if (!next) {
+        next = { path: path.slice(0, i + 1), folders: [], items: [] };
+        node.folders.push(next);
+      }
+      return next;
+    }, root);
+  if (!searching) view.폴더.forEach(at);
+  for (const item of view.items) if (matches(item, text)) at(folderOf(item)).items.push(item);
+  return root;
+}
+
+export const countItems = (node: FolderNode): number =>
+  node.items.length + node.folders.reduce((sum, f) => sum + countItems(f), 0);
+
+/** 모든 폴더 경로(맨 위 제외) — 옮길 곳 고르기 */
+export function listFolders(root: FolderNode): string[][] {
+  return root.folders.flatMap((f) => [f.path, ...listFolders(f)]);
+}
+
+/** 그 열이 들어 있는 폴더 길 — 나무를 그 항목까지 펼칠 때 */
+export function ancestorsOf(view: TreeView, colId: string): string[][] {
+  const item = view.items.find((one) => one.열 === colId);
+  if (!item) return [];
+  const folder = folderOf(item);
+  return folder.map((_, i) => folder.slice(0, i + 1));
+}
diff --git a/M02_MasterTemplete/M02_MasterTemplete_UI_Main.ts b/M02_MasterTemplete/M02_MasterTemplete_UI_Main.ts
index cad56f18..93af24d6 100644
--- a/M02_MasterTemplete/M02_MasterTemplete_UI_Main.ts
+++ b/M02_MasterTemplete/M02_MasterTemplete_UI_Main.ts
@@ -24,6 +24,7 @@ import {
   type StructurePanelHandle,
 } from "./M02_MasterTemplete_Structure";
 import { inputPills } from "./M02_MasterTemplete_Inputs";
+import { askSettle } from "./M02_MasterTemplete_TreePanel_Dialogs";
 import { buildComboBar } from "./M02_MasterTemplete_Combo";
 import { buildComboPanel, type ComboPanel } from "./M02_MasterTemplete_ComboPanel";
 import {
@@ -91,6 +92,10 @@ export interface MainHandle {
   confirmLeave: () => Promise<boolean>;
   /** 양식 밖 화면(좌측 자재 조합 상세)을 띄움 — 머리는 제목만 · 고침 표시 손잡이를 돌려줌 */
   showView: (label: string, node: HTMLElement) => (dirty: boolean) => void;
+  /** 구조물집계표를 열고 그 열을 고름 — 이미 표면 다시 안 읽음(`fresh` 면 다시 읽음) */
+  openTable: (layer: Layer, colId?: string | null, fresh?: boolean) => Promise<void>;
+  /** 나무를 고치기 전 — 저장 안 한 고침이 있으면 저장 · 버림 · 취소를 물음 */
+  settle: () => Promise<false | "clean" | "changed">;
 }
 
 /** 이 층에서 고칠 수 있나 — `isAdmin` = 이 화면 층의 고칠 권한(페이지가 층별로 정함) */
@@ -501,6 +506,28 @@ export function createMain(
     return (d) => (dirty = d);
   }
 
+  async function openTable(layer: Layer, colId?: string | null, fresh = false): Promise<void> {
+    const inTable = sel?.kind === "table" && sel.name === STRUCTURE_TABLE && !fresh;
+    if (!inTable) {
+      if (!fresh && !(await confirmLeave())) return;
+      await open({ layer, projectId: null, kind: "table", name: STRUCTURE_TABLE });
+    }
+    if (colId && sel?.kind === "table") sheet?.selectColumn(colId);
+  }
+
+  async function settle(): Promise<false | "clean" | "changed"> {
+    if (!dirty) return "clean";
+    const choice = await askSettle();
+    if (choice === "cancel") return false;
+    if (choice === "save") {
+      await doSave();
+      return dirty ? false : "changed"; // 저장이 막히면(판 다름 등) 나무도 안 고침
+    }
+    dirty = false; // 버림 — 화면을 서버 그대로 다시 읽음
+    if (sel) await open(sel);
+    return "changed";
+  }
+
   save.addEventListener("click", () => void doSave());
   back.addEventListener("click", async () => {
     const column = sel?.name;
@@ -518,5 +545,5 @@ export function createMain(
   });
   bar();
   empty("");
-  return { root, open, current: () => sel, confirmLeave, showView };
+  return { root, open, current: () => sel, confirmLeave, showView, openTable, settle };
 }
diff --git a/M02_MasterTemplete/M02_MasterTemplete_UI_Page.ts b/M02_MasterTemplete/M02_MasterTemplete_UI_Page.ts
index eca6beac..0870ed02 100644
--- a/M02_MasterTemplete/M02_MasterTemplete_UI_Page.ts
+++ b/M02_MasterTemplete/M02_MasterTemplete_UI_Page.ts
@@ -39,7 +39,13 @@ export async function renderM02MasterTemplate(root: HTMLElement): Promise<void>
     isAdmin,
     () => void side.refresh(),
     () => side.paint(),
-    { top: readOnlyBar?.root, onColumn: (column) => readOnlyBar?.setColumn(column) },
+    {
+      top: readOnlyBar?.root,
+      onColumn: (column) => {
+        readOnlyBar?.setColumn(column);
+        side.selectItem(column);
+      },
+    },
   );
   // 첫 화면 · 닫은 뒤(양식 지움 · 자재 조합 상세 닫음) = 구조물집계표 — 빈 화면 없음
   const home: Selection = {
@@ -55,6 +61,11 @@ export async function renderM02MasterTemplate(root: HTMLElement): Promise<void>
     getOpen: main.current,
     confirmLeave: main.confirmLeave,
     showView: main.showView,
+    tree: {
+      onPick: (item) => void main.openTable(layer, item.열),
+      settle: main.settle,
+      onChanged: (colId) => main.openTable(layer, colId, true),
+    },
   });
 
   const layout = el("div", { className: "ui-workflow-layout m02-master" });
diff --git a/M02_MasterTemplete/M02_MasterTemplete_UI_Side.ts b/M02_MasterTemplete/M02_MasterTemplete_UI_Side.ts
index 4597dd7a..73b1a840 100644
--- a/M02_MasterTemplete/M02_MasterTemplete_UI_Side.ts
+++ b/M02_MasterTemplete/M02_MasterTemplete_UI_Side.ts
@@ -38,6 +38,7 @@ import {
 } from "./M02_MasterTemplete_Structure";
 import { buildMatsetSection } from "./M02_MasterTemplete_Matset";
 import { buildOptionsSection } from "./M02_MasterTemplete_Options";
+import { createTreePanel, type TreePanelOptions } from "./M02_MasterTemplete_TreePanel";
 import { canEdit, type Selection } from "./M02_MasterTemplete_UI_Main";
 
 const KINDS: { kind: Kind; label: () => string }[] = [
@@ -71,6 +72,8 @@ export interface SideOptions {
   confirmLeave: () => Promise<boolean>;
   /** 메인 칸에 양식 밖 화면(자재 조합 상세)을 띄움 */
   showView: (label: string, node: HTMLElement) => (dirty: boolean) => void;
+  /** 항목 나무(26-3a) — 항목 누름 · 고치기 전 저장 처리 · 고친 뒤 표 다시 읽기 */
+  tree: Pick<TreePanelOptions, "onPick" | "settle" | "onChanged">;
 }
 
 export interface SideHandle {
@@ -78,6 +81,8 @@ export interface SideHandle {
   refresh: () => Promise<void>;
   /** 고름 표시를 지금 열린 것 한 줄로 — 편집 칸이 무엇을 열든(카드 [도면 수정] 등) 부름 */
   paint: () => void;
+  /** 표에서 고른 열을 항목 나무에 표시 */
+  selectItem: (colId: string | null) => void;
 }
 
 /** 서버 이름 규칙과 같게 — 화면에서 먼저 막음 */
@@ -150,10 +155,15 @@ export function buildSide(opt: SideOptions): SideHandle {
   );
   summary.classList.remove("is-collapsed");
   summary.classList.add("m02-side__summary");
+  // 항목 나무 — 구조물 집계 양식 아래 · 고르기 모달과 같은 폴더 나무(세 층 공용)
+  const tree = createTreePanel({ layer, canEdit: canEdit(layer, opt.isAdmin), ...opt.tree });
+  const treeSection = section(L("M02_TreeTitle"), tree.root);
+  treeSection.classList.remove("is-collapsed");
   const listHost = el("div", {
     className: "m02-side__lists ui-sidebar-panel",
     children: [
       summary,
+      treeSection,
       // 구조물 옵션 보이기 · 도면 양식은 시스템 층(마스터 템플릿)에만
       ...(layer === "system"
         ? [
@@ -279,7 +289,7 @@ export function buildSide(opt: SideOptions): SideHandle {
     if (mine !== seq) return;
     paintList();
     paintButtons();
-    await Promise.all([refreshStructure(), matset.refresh()]);
+    await Promise.all([refreshStructure(), matset.refresh(), tree.refresh()]);
   }
 
   /* --- 시스템 층 새로 · 본떠 · 지우기(도면 양식만 — 구조물 도면은 집계표 열이 정함) --- */
@@ -360,5 +370,5 @@ export function buildSide(opt: SideOptions): SideHandle {
   }
 
   void refresh();
-  return { root, refresh, paint };
+  return { root, refresh, paint, selectItem: tree.select };
 }
diff --git a/resources/tester/helper_m02_treepanel.cjs b/resources/tester/helper_m02_treepanel.cjs
new file mode 100644
index 00000000..2b7a3be9
--- /dev/null
+++ b/resources/tester/helper_m02_treepanel.cjs
@@ -0,0 +1,54 @@
+/* M02 항목 나무 자료(`M02_MasterTemplete_TreePanel_Model.ts`) 단위검증 헬퍼 — 트랜스파일해 Node 로 돌리고 JSON 으로 냄. */
+const fs = require("fs");
+const path = require("path");
+const ts = require(path.join(__dirname, "..", "..", "config", "node_modules", "typescript"));
+
+const file = path.join(__dirname, "..", "..", "M02_MasterTemplete", "M02_MasterTemplete_TreePanel_Model.ts");
+const js = ts.transpileModule(fs.readFileSync(file, "utf8"), {
+  compilerOptions: { module: ts.ModuleKind.CommonJS, target: ts.ScriptTarget.ES2020 },
+}).outputText;
+const box = { exports: {} };
+new Function("exports", "module", "require", js)(box.exports, box, require);
+const m = box.exports;
+
+const item = (열, 경로, key) => ({ key, 열, 경로, 이름: 경로.join(" "), 단위: "m", 일위대가: null });
+const view = {
+  판: "v1",
+  폴더: [["빈 폴더"], ["돌기슭막이", "빈 아래"]],
+  items: [
+    item("c1", ["돌기슭막이", "메쌓기", "1.2m"], "SS000001"),
+    item("c2", ["돌기슭막이", "찰쌓기"], "SS000002"),
+    item("c3", ["다섯", "둘", "셋", "넷", "잎"], "SS000003"),
+    item("c4", ["최상위 항목"], "SS000004"),
+  ],
+};
+const shape = (n) => ({
+  path: n.path,
+  items: n.items.map((i) => i.열),
+  folders: n.folders.map(shape),
+});
+const all = m.buildFolders(view);
+const found = m.buildFolders(view, "찰쌓기");
+
+process.stdout.write(
+  JSON.stringify({
+    all: shape(all),
+    count: m.countItems(all),
+    found: shape(found),
+    foundCount: m.countItems(found),
+    none: shape(m.buildFolders(view, "없는말")),
+    folders: m.listFolders(all),
+    ancestors: m.ancestorsOf(view, "c3"),
+    ancestorsTop: m.ancestorsOf(view, "c4"),
+    ancestorsNone: m.ancestorsOf(view, "zz"),
+    under: [
+      m.isUnder(["a", "b"], ["a"]),
+      m.isUnder(["a"], ["a"]),
+      m.isUnder(["a"], ["a", "b"]),
+      m.isUnder(["x"], ["a"]),
+    ],
+    leaf: m.leafName(view.items[0]),
+    dir: m.folderOf(view.items[0]),
+    byKey: m.buildFolders(view, "ss000003").items.length + m.buildFolders(view, "SS000003").folders.length,
+  }),
+);
diff --git a/resources/tester/test_m02_layer_screen.py b/resources/tester/test_m02_layer_screen.py
index febeedee..6bd2f25f 100644
--- a/resources/tester/test_m02_layer_screen.py
+++ b/resources/tester/test_m02_layer_screen.py
@@ -104,7 +104,7 @@ def test_층_길_접두어와_고정_풀림():
 def test_읽기만_회사용_개인용으로_복사_막대():
     page = _text(M02 / "M02_MasterTemplete_UI_Page.ts")
     assert 'layer === "company" && !isAdmin ? buildReadOnlyBar(user)' in page
-    assert "onColumn: (column) => readOnlyBar?.setColumn(column)" in page
+    assert "readOnlyBar?.setColumn(column)" in page  # 열 고름 → 막대 · 항목 나무가 함께 받음
     assert "access.needCompany" in page and "buildNeedCompany()" in page
     assert "titleOf(layer)" in page
     layer = _text(LAYER)
diff --git a/resources/tester/test_m02_treepanel.py b/resources/tester/test_m02_treepanel.py
new file mode 100644
index 00000000..798f1391
--- /dev/null
+++ b/resources/tester/test_m02_treepanel.py
@@ -0,0 +1,80 @@
+# -*- coding: utf-8 -*-
+"""M02 관리 화면 항목 나무(PLAN 26-3a) 자료 셈 회귀검증 — 폴더 나무 · 빈 폴더 · 깊이 5 · 찾기 · 폴더 목록.
+
+항목 경로 = 폴더 이름 배열 + 마지막 마디가 항목 이름 · 찾는 글이 있으면 맞는 항목과 위 폴더만.
+Node 헬퍼(`helper_m02_treepanel.cjs`)가 TS 를 트랜스파일해 돌리고, 여기서 값을 판정한다.
+"""
+
+import json
+import os
+import subprocess
+
+import pytest
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+
+
+@pytest.fixture(scope="module")
+def results():
+    proc = subprocess.run(
+        ["node", os.path.join(HERE, "helper_m02_treepanel.cjs")],
+        capture_output=True,
+        text=True,
+        encoding="utf-8",
+        timeout=60,
+    )
+    assert proc.returncode == 0, proc.stderr
+    return json.loads(proc.stdout)
+
+
+def test_빈_폴더도_나무에_있음(results):
+    tops = [f["path"] for f in results["all"]["folders"]]
+    assert ["빈 폴더"] in tops
+    dol = next(f for f in results["all"]["folders"] if f["path"] == ["돌기슭막이"])
+    assert ["돌기슭막이", "빈 아래"] in [f["path"] for f in dol["folders"]]
+
+
+def test_맨_위_항목은_폴더_밖(results):
+    assert results["all"]["items"] == ["c4"]
+    assert results["count"] == 4
+
+
+def test_깊이_5_항목까지_이어짐(results):
+    node = next(f for f in results["all"]["folders"] if f["path"] == ["다섯"])
+    for depth in range(2, 5):
+        node = node["folders"][0]
+        assert len(node["path"]) == depth
+    assert node["items"] == ["c3"]
+
+
+def test_찾기는_맞는_항목과_위_폴더만(results):
+    assert results["foundCount"] == 1
+    assert [f["path"] for f in results["found"]["folders"]] == [["돌기슭막이"]]
+    assert results["found"]["folders"][0]["items"] == ["c2"]  # 빈 폴더는 안 보임
+    assert results["none"] == {"path": [], "items": [], "folders": []}
+
+
+def test_키로도_찾음(results):
+    assert results["byKey"] == 1
+
+
+def test_폴더_목록과_위_길(results):
+    assert ["다섯", "둘", "셋", "넷"] in results["folders"]
+    assert ["빈 폴더"] in results["folders"]
+    assert results["ancestors"] == [
+        ["다섯"],
+        ["다섯", "둘"],
+        ["다섯", "둘", "셋"],
+        ["다섯", "둘", "셋", "넷"],
+    ]
+    assert results["ancestorsTop"] == []
+    assert results["ancestorsNone"] == []
+
+
+def test_안_또는_같음_판정(results):
+    assert results["under"] == [True, True, False, False]
+
+
+def test_잎_이름과_폴더(results):
+    assert results["leaf"] == "1.2m"
+    assert results["dir"] == ["돌기슭막이", "메쌓기"]
diff --git a/ui_template/ui_template_locale_m2.ts b/ui_template/ui_template_locale_m2.ts
index f9b30d72..e6db41f1 100644
--- a/ui_template/ui_template_locale_m2.ts
+++ b/ui_template/ui_template_locale_m2.ts
@@ -97,4 +97,42 @@ export const ui_locales_m2 = {
   M02_PickerManage: ["관리 화면에서 고치기", "Edit in manager"],
   M02_PickerCopied: ["개인용으로 복사했음", "Copied to personal"],
   M02_PickerCopyFailed: ["복사 못 함 — {value}", "Copy failed — {value}"],
+  M02_TreeTitle: ["항목 나무", "Item tree"],
+  M02_TreeSearch: ["항목 찾기", "Find item"],
+  M02_TreeEmptyEdit: [
+    "항목이 없음 — 맨 위 줄을 오른쪽 클릭해 폴더 · 항목을 더함",
+    "No items — right-click the top row to add a folder or item",
+  ],
+  M02_TreeEmpty: ["항목이 없음", "No items"],
+  M02_TreeNoHit: ["찾은 항목이 없음", "No matching item"],
+  M02_TreeAddFolder: ["폴더 더하기", "Add folder"],
+  M02_TreeAddItem: ["항목 더하기", "Add item"],
+  M02_TreeRename: ["이름 바꾸기", "Rename"],
+  M02_TreeMove: ["옮기기", "Move"],
+  M02_TreeFolderName: ["폴더 이름", "Folder name"],
+  M02_TreeItemName: ["항목 이름", "Item name"],
+  M02_TreeUnit: ["단위", "Unit"],
+  M02_TreeMoveTo: ["옮길 폴더", "Move to"],
+  M02_TreeTop: ["맨 위 (폴더 밖)", "Top (no folder)"],
+  M02_TreeOk: ["확인", "OK"],
+  M02_TreeCancel: ["취소", "Cancel"],
+  M02_TreeDeleteFolder: [
+    "「{value}」 폴더와 안의 항목 {n}개를 지움 — 이미 쓰는 프로젝트에는 영향 없음(프로젝트는 복사본을 씀)",
+    "Delete folder “{value}” and its {n} item(s) — projects already using them are not affected (they keep their own copies)",
+  ],
+  M02_TreeDeleteItem: [
+    "「{value}」 항목을 지움 — 이미 쓰는 프로젝트에는 영향 없음(프로젝트는 복사본을 씀)",
+    "Delete item “{value}” — projects already using it are not affected (they keep their own copies)",
+  ],
+  M02_TreeStale: [
+    "그 사이 나무가 바뀜 — 다시 읽었음, 한 번 더 해 볼 것",
+    "The tree changed meanwhile — reloaded, try again",
+  ],
+  M02_TreeUnsaved: [
+    "저장 안 한 표 고침이 있음 — 나무를 고치기 전에 처리",
+    "Unsaved table edits — settle them before changing the tree",
+  ],
+  M02_TreeSaveGo: ["저장하고 계속", "Save and continue"],
+  M02_TreeDiscardGo: ["버리고 계속", "Discard and continue"],
+  M02_TreeDone: ["나무를 고침", "Tree updated"],
 } as const;