diff --git a/A00_Common/spreadsheet/spreadsheet_text.ts b/A00_Common/spreadsheet/spreadsheet_text.ts
index df33f3d5..1928550f 100644
--- a/A00_Common/spreadsheet/spreadsheet_text.ts
+++ b/A00_Common/spreadsheet/spreadsheet_text.ts
@@ -95,6 +95,14 @@ const TEXT = {
     "병합된 셀의 일부를 바꿀 수 없습니다",
     "Can't change part of a merged cell",
   ],
+  Unit: ["단위", "Unit"],
+  UnitGroup_area: ["넓이·부피·길이", "Area · volume · length"],
+  UnitGroup_weight: ["무게·부피(액체)", "Weight · liquid volume"],
+  UnitGroup_count: ["개수", "Count"],
+  UnitGroup_rate: ["속도·각도·비율", "Speed · angle · rate"],
+  UnitGroup_op: ["연산·비교", "Operators"],
+  UnitRecent: ["최근 씀", "Recently used"],
+  UnitAsFormat: ["숫자 형식으로 붙이기", "Attach as number format"],
 } as const;
 
 export function st(key: keyof typeof TEXT): string {
diff --git a/A00_Common/spreadsheet/spreadsheet_toolbar.css b/A00_Common/spreadsheet/spreadsheet_toolbar.css
index d43a375f..214b2f33 100644
--- a/A00_Common/spreadsheet/spreadsheet_toolbar.css
+++ b/A00_Common/spreadsheet/spreadsheet_toolbar.css
@@ -119,6 +119,32 @@
   gap: var(--spacing-4);
 }
 
+.ss-toolbar__unit-pop {
+  max-height: 340px;
+  overflow-y: auto;
+}
+
+.ss-toolbar__unit-section + .ss-toolbar__unit-section {
+  margin-top: var(--spacing-8);
+}
+
+.ss-toolbar__unit-label {
+  margin-bottom: var(--spacing-4);
+  color: var(--color-text-muted);
+  font-size: 0.72rem;
+}
+
+.ss-toolbar__unit-grid {
+  display: grid;
+  grid-template-columns: repeat(4, 1fr);
+  gap: var(--spacing-4);
+}
+
+.ss-toolbar__unit-btn {
+  min-width: 0;
+  padding: 4px 2px;
+}
+
 /* ── 시트 탭 ─────────────────────────────────────────────────────────────── */
 
 .ss-tabs {
diff --git a/A00_Common/spreadsheet/spreadsheet_toolbar.ts b/A00_Common/spreadsheet/spreadsheet_toolbar.ts
index e5ffd09c..90577706 100644
--- a/A00_Common/spreadsheet/spreadsheet_toolbar.ts
+++ b/A00_Common/spreadsheet/spreadsheet_toolbar.ts
@@ -12,6 +12,7 @@
 
 import { createButton, el } from "@ui/ui_template_elements";
 import { colName, rangeToA1, toA1 } from "./spreadsheet_address";
+import { cellToText, textToCell } from "./spreadsheet_editor";
 import { st } from "./spreadsheet_text";
 import type { BorderLine, BorderSide, CellRange, CellStyle, Command } from "./spreadsheet_types";
 import type { PartHandle, SpreadsheetContext } from "./spreadsheet_view_types";
@@ -58,6 +59,43 @@ const BORDER_LINES: BorderLine[] = [
   "dashed",
 ];
 
+type TextKey = Parameters<typeof st>[0];
+
+const UNIT_GROUPS: [label: TextKey, items: string[]][] = [
+  ["UnitGroup_area", ["㎡", "㎥", "m", "㎝", "㎜", "㎞"]],
+  ["UnitGroup_weight", ["kg", "t", "ℓ", "㎖"]],
+  ["UnitGroup_count", ["개", "본", "식", "EA", "매"]],
+  ["UnitGroup_rate", ["m/s", "°", "%", "‰"]],
+  ["UnitGroup_op", ["×", "÷", "±", "≤", "≥", "Σ"]],
+];
+const UNIT_RECENT_MAX = 8;
+const UNIT_RECENT_KEY = "aislo-ss-recent-units";
+
+function loadRecentUnits(): string[] {
+  try {
+    const raw = localStorage.getItem(UNIT_RECENT_KEY);
+    return raw ? (JSON.parse(raw) as string[]) : [];
+  } catch {
+    return [];
+  }
+}
+
+function pushRecentUnit(unit: string): string[] {
+  const list = [unit, ...loadRecentUnits().filter((u) => u !== unit)].slice(0, UNIT_RECENT_MAX);
+  try {
+    localStorage.setItem(UNIT_RECENT_KEY, JSON.stringify(list));
+  } catch {
+    /* 저장 못 해도 이번 넣기는 그대로 진행 */
+  }
+  return list;
+}
+
+/** 숫자 형식 코드 끝 따옴표 글자(전에 붙인 단위)를 떼고 새 단위를 붙임 — 없으면 "0" 에서 시작. */
+function attachUnitToFormat(code: string, unit: string): string {
+  const base = (code || "0").replace(/"[^"]*"\s*$/, "");
+  return base + `"${unit}"`;
+}
+
 /** 활성 칸에 지금 걸린 서식 — 칸 자기 것 없으면 열 · 행 · 시트 기본(`Sheet.기본.서식`) · 그다음 0. */
 function styleAt(ctx: SpreadsheetContext, r: number, c: number): CellStyle {
   const sheet = ctx.sheet();
@@ -332,6 +370,88 @@ export function mountToolbar(ctx: SpreadsheetContext): PartHandle {
   numfmtInput.append(numfmtList);
   numfmtInput.addEventListener("change", () => patch({ 형식: numfmtInput.value || null }));
 
+  // ── 단위 기호 ─────────────────────────────────────────────────────────
+  const unitBtn = createButton({ label: `${st("Unit")} ▾`, variant: "ghost" });
+  const unitPop = el("div", {
+    className: "ss-toolbar__popover ss-toolbar__unit-pop",
+    attrs: { hidden: "true" },
+  });
+  const unitAsFormat = el("input", { attrs: { type: "checkbox", id: "ss-unit-as-format" } });
+  const unitAsFormatRow = el("label", {
+    className: "ss-toolbar__popover-row",
+    attrs: { for: "ss-unit-as-format" },
+    children: [unitAsFormat, el("span", { text: st("UnitAsFormat") })],
+  });
+  const recentGrid = el("div", { className: "ss-toolbar__unit-grid" });
+  const recentSection = el("div", {
+    className: "ss-toolbar__unit-section",
+    attrs: { hidden: "true" },
+    children: [
+      el("div", { className: "ss-toolbar__unit-label", text: st("UnitRecent") }),
+      recentGrid,
+    ],
+  });
+
+  function insertUnit(unit: string): void {
+    if (ctx.editor.editing()) {
+      const active = document.activeElement;
+      if (active instanceof HTMLTextAreaElement && ctx.root.contains(active)) {
+        const s = active.selectionStart ?? active.value.length;
+        const e = active.selectionEnd ?? active.value.length;
+        active.value = active.value.slice(0, s) + unit + active.value.slice(e);
+        active.setSelectionRange(s + unit.length, s + unit.length);
+        active.dispatchEvent(new Event("input", { bubbles: true }));
+      }
+    } else if (unitAsFormat.checked) {
+      const { r, c } = ctx.selection.활성;
+      patch({ 형식: attachUnitToFormat(styleAt(ctx, r, c).형식 ?? "", unit) });
+    } else {
+      const { r, c } = ctx.selection.활성;
+      const sheet = ctx.sheet();
+      const key = toA1(r, c);
+      const text = cellToText(sheet.칸[key]) + unit;
+      ctx.dispatch({ 종류: "칸", 시트: sheet.id, 칸: { [key]: textToCell(text, sheet.칸[key]) } });
+    }
+    renderRecent(pushRecentUnit(unit));
+    unitPop.hidden = true;
+  }
+
+  function renderRecent(list: string[]): void {
+    recentGrid.textContent = "";
+    recentSection.hidden = list.length === 0;
+    for (const u of list) {
+      const b = createButton({ label: u, variant: "ghost", onClick: () => insertUnit(u) });
+      b.className += " ss-toolbar__unit-btn";
+      recentGrid.append(b);
+    }
+  }
+  renderRecent(loadRecentUnits());
+
+  unitPop.append(unitAsFormatRow, recentSection);
+  for (const [labelKey, items] of UNIT_GROUPS) {
+    const grid = el("div", { className: "ss-toolbar__unit-grid" });
+    for (const u of items) {
+      const b = createButton({ label: u, variant: "ghost", onClick: () => insertUnit(u) });
+      b.className += " ss-toolbar__unit-btn";
+      grid.append(b);
+    }
+    unitPop.append(
+      el("div", {
+        className: "ss-toolbar__unit-section",
+        children: [el("div", { className: "ss-toolbar__unit-label", text: st(labelKey) }), grid],
+      }),
+    );
+  }
+  unitBtn.addEventListener("click", (ev) => {
+    ev.stopPropagation();
+    unitPop.hidden = !unitPop.hidden;
+  });
+  unitPop.addEventListener("click", (ev) => ev.stopPropagation());
+  const closeUnitPop = (): void => {
+    unitPop.hidden = true;
+  };
+  document.addEventListener("click", closeUnitPop);
+
   root.append(
     group(undoBtn, redoBtn),
     group(fontInput, sizeInput),
@@ -341,6 +461,7 @@ export function mountToolbar(ctx: SpreadsheetContext): PartHandle {
     group(mergeBtn),
     group(borderBtn, borderPop),
     group(numfmtInput),
+    group(unitBtn, unitPop),
   );
 
   function refresh(): void {
@@ -383,6 +504,7 @@ export function mountToolbar(ctx: SpreadsheetContext): PartHandle {
     refresh,
     destroy() {
       document.removeEventListener("click", closeBorderPop);
+      document.removeEventListener("click", closeUnitPop);
       root.remove();
     },
   };
diff --git a/resources/tester/spreadsheet/e_harness.ts b/resources/tester/spreadsheet/e_harness.ts
index eae07abd..09a0775c 100644
--- a/resources/tester/spreadsheet/e_harness.ts
+++ b/resources/tester/spreadsheet/e_harness.ts
@@ -75,7 +75,9 @@ const grid: GridHandle = {
   destroy() {},
 };
 
-function applyAndRefresh(command: import("../../../A00_Common/spreadsheet/spreadsheet_types").Command): void {
+function applyAndRefresh(
+  command: import("../../../A00_Common/spreadsheet/spreadsheet_types").Command,
+): void {
   const effect = applyCommand(book, command);
   if (effect.rebuild) engine.rebuild(book);
   else engine.update(effect.cells);
@@ -126,7 +128,7 @@ const ctx: SpreadsheetContext = {
   },
   grid,
   editor: {
-    editing: () => false,
+    editing: () => editingFlag,
     begin() {},
     commit() {},
     cancel() {},
@@ -134,6 +136,24 @@ const ctx: SpreadsheetContext = {
   },
 };
 
+// 단위 기호 [편집 중이면 커서 자리에] 갈래 시험용 — 진짜 D 편집기 대신 숨은 textarea 하나로 흉내.
+let editingFlag = false;
+const fakeEditorTa = document.createElement("textarea");
+fakeEditorTa.id = "fake-editor-ta";
+root.append(fakeEditorTa);
+(window as unknown as { __setEditing: (on: boolean, value?: string) => void }).__setEditing = (
+  on,
+  value,
+) => {
+  editingFlag = on;
+  if (on) {
+    if (value !== undefined) fakeEditorTa.value = value;
+    fakeEditorTa.focus();
+  } else {
+    fakeEditorTa.blur();
+  }
+};
+
 const toolbar = mountToolbar(ctx);
 const tabs = mountTabs(ctx);
 attachMenu(ctx);