diff --git a/B05_Profile/B05_Profile_Structures_Repository.py b/B05_Profile/B05_Profile_Structures_Repository.py
index e337c46d..30ae8a44 100644
--- a/B05_Profile/B05_Profile_Structures_Repository.py
+++ b/B05_Profile/B05_Profile_Structures_Repository.py
@@ -14,6 +14,7 @@ from typing import Any, Iterable
 
 from B05_Profile.B05_Profile_Structures_Schema import StructureInstance, structure_type_map
 from common_util.common_util_json import atomic_write_json
+from M02_MasterTemplete.M02_MasterTemplete_Options import hidden_keys
 
 STRUCTURES_FILE_NAME = "structures.json"
 _STAGE_DIR = os.path.join("B05_Profile", "route")
@@ -168,6 +169,7 @@ def _validate_types(items: list[StructureInstance]) -> None:
     들어간다(2026-08-16 크로스체크 지적 2). 정본에 닿는 마지막 관문은 여기다.
     """
     types = structure_type_map()
+    hidden = hidden_keys()  # M02 「구조물 옵션 보이기」 — 숨긴 옵션은 필수 아님
     for item in items:
         definition = types.get(item.type_id)
         if definition is None:
@@ -182,10 +184,10 @@ def _validate_types(items: list[StructureInstance]) -> None:
                 f"{definition.name}의 배치형태는 {definition.placement}인데 "
                 f"{item.placement}로 보냈습니다."
             )
-        _validate_options(item, definition)
+        _validate_options(item, definition, hidden.get(item.type_id, set()))
 
 
-def _validate_options(item: StructureInstance, definition) -> None:
+def _validate_options(item: StructureInstance, definition, hidden: set[str] = frozenset()) -> None:
     allowed = {option.key: option for option in definition.options}
     for key, value in item.options.items():
         option = allowed.get(key)
@@ -203,6 +205,8 @@ def _validate_options(item: StructureInstance, definition) -> None:
         # 강제하지 않는다. 필수 원칙은 유지되고 시점만 미뤄진다(2026-08-17 사용자 확정).
         if option.phase == "detail":
             continue
+        if option.key in hidden:  # 화면에서 숨긴 옵션은 값을 못 넣으므로 필수로 안 침
+            continue
         if option.required and item.options.get(option.key) in (None, ""):
             raise ValueError(
                 f"{definition.name}의 {option.label}은(는) 필수 입력입니다 — "
diff --git a/M02_MasterTemplete/M02_MasterTemplete_Options.py b/M02_MasterTemplete/M02_MasterTemplete_Options.py
index 8936080b..e5fb5514 100644
--- a/M02_MasterTemplete/M02_MasterTemplete_Options.py
+++ b/M02_MasterTemplete/M02_MasterTemplete_Options.py
@@ -65,6 +65,20 @@ def _shown(doc: dict[str, Any], type_id: str, key: str) -> bool:
     return not (isinstance(row, dict) and row.get(key) is False)
 
 
+def hidden_keys() -> dict[str, set[str]]:
+    """숨긴 옵션(종류 → 키 집합) — 저장 검증이 숨긴 옵션을 필수로 안 침 · 깨진 표는 모두 보임."""
+    try:
+        doc = _load()[0]
+    except store.StoreError as e:
+        logger.warning("구조물 옵션 표시 표를 못 읽어 모두 보임으로 봄 — %s", e.detail)
+        return {}
+    return {
+        type_id: {key for key, shown in row.items() if shown is False}
+        for type_id, row in doc.items()
+        if isinstance(row, dict)
+    }
+
+
 def with_visible() -> TypesWithVisible:
     """레지스트리 정본 + 보임 여부 — 파일이 깨졌으면 모두 보임(폼이 죽지 않게 · 로그만)."""
     try:
diff --git a/M02_MasterTemplete/M02_MasterTemplete_Options_Text.ts b/M02_MasterTemplete/M02_MasterTemplete_Options_Text.ts
index 365d8c3a..206a0c35 100644
--- a/M02_MasterTemplete/M02_MasterTemplete_Options_Text.ts
+++ b/M02_MasterTemplete/M02_MasterTemplete_Options_Text.ts
@@ -21,8 +21,8 @@ const TEXT = {
   Detail: ["B06 전용", "B06 only"],
   Required: ["필수", "Required"],
   RequiredTip: [
-    "필수 옵션 — 숨기면 B05 폼에서 값을 못 넣어 저장이 막힐 수 있음",
-    "Required — hiding it leaves the B05 form unable to set it",
+    "필수 옵션 — 숨기면 폼에 안 나오고 필수로도 안 침(저장이 안 막힘)",
+    "Required — when hidden it is not shown and not enforced",
   ],
   Save: ["저장", "Save"],
   ShowAll: ["모두 보임", "Show all"],
diff --git a/resources/tester/test_m02_structure_options.py b/resources/tester/test_m02_structure_options.py
index e856d406..fe9d9090 100644
--- a/resources/tester/test_m02_structure_options.py
+++ b/resources/tester/test_m02_structure_options.py
@@ -27,6 +27,10 @@ URL = "/api/m02/structure-options"
 TYPES = "/api/projects/structure-types"
 
 
+def structure_type(type_id):
+    return next(t for t in load_structure_types() if t.type_id == type_id)
+
+
 @pytest.fixture
 def client(tmp_path: Path, monkeypatch) -> TestClient:
     monkeypatch.setattr(store, "FOLDER", tmp_path)
@@ -127,3 +131,38 @@ def test_좌측_줄은_구조물_집계_양식_아래_한_줄_같은_한_곳에
     )
     ui = (ROOT / "M02_MasterTemplete/M02_MasterTemplete_Options.ts").read_text("utf-8")
     assert 'o.phase === "detail"' in ui  # B06 전용 표시
+
+
+def test_숨긴_옵션은_필수_아님_저장이_안_막힘(client, tmp_path, monkeypatch) -> None:
+    """B05 필수(기본값 없음) 옵션 — 보이면 막고 숨기면 저장됨(다른 필수는 그대로)."""
+    from B05_Profile import B05_Profile_Structures_Repository as repo
+    from B05_Profile.B05_Profile_Structures_Schema import (
+        StructureInstance,
+        StructureOptionField,
+        StructureType,
+    )
+
+    def must(key):
+        return StructureOptionField(key=key, label=key, input="number", required=True, phase="b05")
+
+    fake = StructureType(
+        type_id="fake_hide",
+        group="Z",
+        name="가짜",
+        placement="point",
+        options=[must("a"), must("b")],
+    )
+    real = repo.structure_type_map()
+    monkeypatch.setattr(repo, "structure_type_map", lambda: {**real, "fake_hide": fake})
+    item = lambda opts: StructureInstance.model_validate(  # noqa: E731
+        {"type_id": "fake_hide", "placement": "point", "chainage_m": 10.0, "options": opts}
+    )
+    root = str(tmp_path / "project")
+    with pytest.raises(ValueError, match="필수"):
+        repo.save_structures(root, [item({})], base_revision=0)  # 보임 = 필수 그대로
+    (store.FOLDER / opt.FILE).write_text('{"fake_hide": {"a": false}}', encoding="utf-8")
+    with pytest.raises(ValueError, match="필수"):  # a 는 숨겨 통과 · b 는 여전히 필수
+        repo.save_structures(root, [item({})], base_revision=0)
+    assert (
+        repo.save_structures(root, [item({"b": 3})], base_revision=0) == 1
+    )  # 숨긴 a 는 빈 채 저장