diff --git a/app/services/summarizer.py b/app/services/summarizer.py
index 061ed2a..f359f67 100644
--- a/app/services/summarizer.py
+++ b/app/services/summarizer.py
@@ -8,6 +8,24 @@
 client = OpenAI(api_key=settings.openai_api_key)
 
 
+def _to_text(value) -> str:
+    if value is None:
+        return ""
+
+    if isinstance(value, str):
+        return value.strip()
+
+    if isinstance(value, list):
+        return "\n".join(text for item in value if (text := _to_text(item)))
+
+    if isinstance(value, dict):
+        return "\n".join(
+            f"{key}: {text}" for key, val in value.items() if (text := _to_text(val))
+        )
+
+    return str(value)
+
+
 def summarize_notice(title: str, content: str) -> NoticeSummaryData:
     settings = get_settings()
     prompt = f"""
@@ -39,9 +57,9 @@ def summarize_notice(title: str, content: str) -> NoticeSummaryData:
     payload = json.loads(response_text)
 
     return NoticeSummaryData(
-        summary=payload["summary"],
-        target_info=payload.get("target_info"),
-        schedule_info=payload.get("schedule_info"),
-        caution_info=payload.get("caution_info"),
+        summary=_to_text(payload.get("summary")),
+        target_info=_to_text(payload.get("target_info")),
+        schedule_info=_to_text(payload.get("schedule_info")),
+        caution_info=_to_text(payload.get("caution_info")),
         generated_model=response.model,
     )
diff --git a/tests/test_summarizer.py b/tests/test_summarizer.py
new file mode 100644
index 0000000..7a388c9
--- /dev/null
+++ b/tests/test_summarizer.py
@@ -0,0 +1,41 @@
+import json
+from types import SimpleNamespace
+
+from app.services import summarizer
+
+
+def test_summarize_notice_normalizes_structured_llm_fields(monkeypatch) -> None:
+    payload = {
+        "summary": {"핵심": "생활관 소독 안내입니다."},
+        "target_info": {"소독 대상": "전체 생활관"},
+        "schedule_info": {"일시": "2026년 5월 8일 10시"},
+        "caution_info": ["귀중품은 보관해 주세요.", "소독 시간에는 협조 바랍니다."],
+    }
+
+    fake_response = SimpleNamespace(
+        choices=[
+            SimpleNamespace(
+                message=SimpleNamespace(content=json.dumps(payload, ensure_ascii=False))
+            )
+        ],
+        model="fake-model",
+    )
+    fake_client = SimpleNamespace(
+        chat=SimpleNamespace(
+            completions=SimpleNamespace(create=lambda **_kwargs: fake_response)
+        )
+    )
+    monkeypatch.setattr(summarizer, "client", fake_client)
+
+    result = summarizer.summarize_notice("소독 안내", "생활관 소독을 진행합니다.")
+
+    assert result.summary == "핵심: 생활관 소독 안내입니다."
+    assert result.target_info == "소독 대상: 전체 생활관"
+    assert result.schedule_info == "일시: 2026년 5월 8일 10시"
+    assert result.caution_info == "귀중품은 보관해 주세요.\n소독 시간에는 협조 바랍니다."
+    assert result.generated_model == "fake-model"
+
+
+def test_to_text_omits_empty_nested_values() -> None:
+    assert summarizer._to_text(["A", None, "  ", "B"]) == "A\nB"
+    assert summarizer._to_text({"대상": "전체", "비고": None, "공백": "  "}) == "대상: 전체"