diff --git a/app/workers/extract_worker.py b/app/workers/extract_worker.py
index 9bf29a2..6f9db5d 100644
--- a/app/workers/extract_worker.py
+++ b/app/workers/extract_worker.py
@@ -89,21 +89,30 @@ async def process(document_id: int, session: AsyncSession) -> None:
         tmp_input = tmp_dir / f"input_{document_id}.{fmt}"
         shutil.copy2(str(full_path), str(tmp_input))
 
+        # 스프레드시트는 csv, 나머지는 txt
+        CALC_FORMATS = {"xlsx", "xls", "ods", "osheet"}
+        if fmt in CALC_FORMATS:
+            convert_to = "csv:Text - txt - csv (StarCalc):44,34,76,1"
+            out_ext = "csv"
+        else:
+            convert_to = "txt:Text"
+            out_ext = "txt"
+
         try:
             result = subprocess.run(
-                ["libreoffice", "--headless", "--convert-to", "txt:Text", "--outdir", str(tmp_dir), str(tmp_input)],
+                ["libreoffice", "--headless", "--convert-to", convert_to, "--outdir", str(tmp_dir), str(tmp_input)],
                 capture_output=True, text=True, timeout=60,
             )
-            txt_file = tmp_dir / f"input_{document_id}.txt"
-            if txt_file.exists():
-                text = txt_file.read_text(encoding="utf-8", errors="replace")
+            out_file = tmp_dir / f"input_{document_id}.{out_ext}"
+            if out_file.exists():
+                text = out_file.read_text(encoding="utf-8", errors="replace")
                 doc.extracted_text = text[:15000]
                 doc.extracted_at = datetime.now(timezone.utc)
                 doc.extractor_version = "libreoffice"
-                txt_file.unlink()
+                out_file.unlink()
                 logger.info(f"[LibreOffice] {doc.file_path} ({len(text)}자)")
             else:
-                raise RuntimeError(f"LibreOffice 변환 결과물 없음: {result.stderr[:200]}")
+                raise RuntimeError(f"LibreOffice 변환 실패: {result.stderr[:300]}")
         except subprocess.TimeoutExpired:
             raise RuntimeError(f"LibreOffice 텍스트 추출 timeout (60s)")
         finally: