diff --git a/CLAUDE.md b/CLAUDE.md
index 6df8bff..5e113c0 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -6,6 +6,7 @@
 
 現在の進捗: Step 1〜5 完了（撮影・保存・一覧・削除の実装完了）．初期バージョンのアプリが動作する状態．
 ※ 撮影→保存の高速化完了（YUV→PNG 変換を Android ネイティブに移行，非圧縮 PNG + 回転統合により 15 秒 → 約 2 秒に短縮）
+※ カメラ診断機能のインフラ追加完了（`DiagnosticsProvider` / `RawCaptureService.getCameraDiagnostics` / `FileService.saveDiagnosticsJson`）．UI は非表示．AQUOS sense3 のフロントカメラは **HW Level 3 + RAW (DNG) + MANUAL_SENSOR + MANUAL_POST_PROCESSING** 対応を確認．次は定量モード撮影機能（DNG 経路）の実装．
 ※ ステップ完了時にここを更新すること．
 
 ## 必須ルール（コード実装時）
diff --git a/android/app/src/main/kotlin/com/example/mini_tias/RawCapturePlugin.kt b/android/app/src/main/kotlin/com/example/mini_tias/RawCapturePlugin.kt
index 9324ef1..589a200 100644
--- a/android/app/src/main/kotlin/com/example/mini_tias/RawCapturePlugin.kt
+++ b/android/app/src/main/kotlin/com/example/mini_tias/RawCapturePlugin.kt
@@ -77,6 +77,7 @@
                     result.error("SOUND_ERROR", "保存完了音の再生に失敗: ${e.message}", null)
                 }
             }
+            "getCameraDiagnostics" -> getCameraDiagnostics(result)
             else -> result.notImplemented()
         }
     }
@@ -443,6 +444,92 @@
         out.write(ByteBuffer.allocate(4).putInt(crc.value.toInt()).array())
     }
 
+    /**
+     * フロントカメラの Camera2 API 能力を読み出して Map で返す．
+     *
+     * CameraCharacteristics から各種パラメータを取得し，null セーフに処理する．
+     * フロントカメラが見つからない場合は error を返す．
+     */
+    private fun getCameraDiagnostics(result: MethodChannel.Result) {
+        val cameraManager = context.getSystemService(Context.CAMERA_SERVICE) as CameraManager
+
+        val cameraId = cameraManager.cameraIdList.firstOrNull { id ->
+            val characteristics = cameraManager.getCameraCharacteristics(id)
+            characteristics.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_FRONT
+        }
+
+        if (cameraId == null) {
+            result.error("NO_CAMERA", "フロントカメラが見つかりません", null)
+            return
+        }
+
+        val c = cameraManager.getCameraCharacteristics(cameraId)
+        val streamConfigMap = c.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP)
+
+        // rawOutputSizes
+        val rawOutputSizes = streamConfigMap
+            ?.getOutputSizes(ImageFormat.RAW_SENSOR)
+            ?.map { "${it.width}x${it.height}" }
+            ?: emptyList<String>()
+
+        // yuvOutputSizes
+        val yuvOutputSizes = streamConfigMap
+            ?.getOutputSizes(ImageFormat.YUV_420_888)
+            ?.map { "${it.width}x${it.height}" }
+            ?: emptyList<String>()
+
+        // jpegOutputSizes
+        val jpegOutputSizes = streamConfigMap
+            ?.getOutputSizes(ImageFormat.JPEG)
+            ?.map { "${it.width}x${it.height}" }
+            ?: emptyList<String>()
+
+        val diagnostics = mapOf<String, Any?>(
+            "cameraId" to cameraId,
+            "hardwareLevel" to c.get(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL),
+            "capabilities" to c.get(CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES)?.toList(),
+            "exposureTimeRangeNs" to c.get(CameraCharacteristics.SENSOR_INFO_EXPOSURE_TIME_RANGE)
+                ?.let { listOf(it.lower, it.upper) },
+            "sensitivityRange" to c.get(CameraCharacteristics.SENSOR_INFO_SENSITIVITY_RANGE)
+                ?.let { listOf(it.lower, it.upper) },
+            "lscMapSize" to null,  // 実キャプチャ後に CaptureResult から取得する必要があるため診断段階では null
+            "availableLensShadingMapModes" to c.get(
+                CameraCharacteristics.STATISTICS_INFO_AVAILABLE_LENS_SHADING_MAP_MODES
+            )?.map { it },
+            "availableNoiseReductionModes" to c.get(
+                CameraCharacteristics.NOISE_REDUCTION_AVAILABLE_NOISE_REDUCTION_MODES
+            )?.toList(),
+            "availableEdgeModes" to c.get(CameraCharacteristics.EDGE_AVAILABLE_EDGE_MODES)?.toList(),
+            "availableTonemapModes" to c.get(
+                CameraCharacteristics.TONEMAP_AVAILABLE_TONE_MAP_MODES
+            )?.toList(),
+            "availableShadingModes" to c.get(CameraCharacteristics.SHADING_AVAILABLE_MODES)?.toList(),
+            "availableAwbModes" to c.get(
+                CameraCharacteristics.CONTROL_AWB_AVAILABLE_MODES
+            )?.toList(),
+            "availableAfModes" to c.get(
+                CameraCharacteristics.CONTROL_AF_AVAILABLE_MODES
+            )?.toList(),
+            "minFocusDistance" to c.get(CameraCharacteristics.LENS_INFO_MINIMUM_FOCUS_DISTANCE),
+            "hyperfocalDistance" to c.get(CameraCharacteristics.LENS_INFO_HYPERFOCAL_DISTANCE),
+            "rawOutputSizes" to rawOutputSizes,
+            "yuvOutputSizes" to yuvOutputSizes,
+            "jpegOutputSizes" to jpegOutputSizes,
+            "colorFilterArrangement" to c.get(
+                CameraCharacteristics.SENSOR_INFO_COLOR_FILTER_ARRANGEMENT
+            ),
+            "blackLevelPattern" to c.get(CameraCharacteristics.SENSOR_BLACK_LEVEL_PATTERN)?.toString(),
+            "whiteLevel" to c.get(CameraCharacteristics.SENSOR_INFO_WHITE_LEVEL),
+            "physicalSize" to c.get(CameraCharacteristics.SENSOR_INFO_PHYSICAL_SIZE)
+                ?.let { listOf(it.width, it.height) },
+            "pixelArraySize" to c.get(CameraCharacteristics.SENSOR_INFO_PIXEL_ARRAY_SIZE)
+                ?.let { listOf(it.width, it.height) },
+            "activeArraySize" to c.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE)?.toString(),
+        )
+
+        result.success(diagnostics)
+    }
+
     private fun cleanup() {
         cameraDevice?.close()
         cameraDevice = null
diff --git a/lib/main.dart b/lib/main.dart
index 87089bf..d024a8a 100644
--- a/lib/main.dart
+++ b/lib/main.dart
@@ -4,6 +4,7 @@
 
 import 'package:mini_tias/app.dart';
 import 'package:mini_tias/providers/camera_provider.dart';
+import 'package:mini_tias/providers/diagnostics_provider.dart';
 import 'package:mini_tias/providers/gallery_provider.dart';
 
 void main() {
@@ -15,6 +16,7 @@
       providers: [
         ChangeNotifierProvider(create: (_) => CameraProvider()),
         ChangeNotifierProvider(create: (_) => GalleryProvider()),
+        ChangeNotifierProvider(create: (_) => DiagnosticsProvider()),
       ],
       child: const MiniTiasApp(),
     ),
diff --git a/lib/providers/diagnostics_provider.dart b/lib/providers/diagnostics_provider.dart
new file mode 100644
index 0000000..05011bd
--- /dev/null
+++ b/lib/providers/diagnostics_provider.dart
@@ -0,0 +1,55 @@
+import 'package:flutter/foundation.dart';
+
+import 'package:mini_tias/services/file_service.dart';
+import 'package:mini_tias/services/raw_capture_service.dart';
+
+/// カメラ診断機能の状態管理．
+/// Camera2 API の能力を読み出し JSON ファイルに保存する．
+class DiagnosticsProvider extends ChangeNotifier {
+  final RawCaptureService _rawCaptureService;
+  final FileService _fileService;
+
+  DiagnosticsProvider({
+    RawCaptureService? rawCaptureService,
+    FileService? fileService,
+  }) : _rawCaptureService = rawCaptureService ?? RawCaptureService(),
+       _fileService = fileService ?? FileService();
+
+  bool _isRunning = false;
+  String? _lastSavedPath;
+  String? _errorMessage;
+
+  bool get isRunning => _isRunning;
+  String? get lastSavedPath => _lastSavedPath;
+  String? get errorMessage => _errorMessage;
+
+  /// 診断を実行し，結果を JSON ファイルとして保存する．
+  Future<void> runDiagnostics() async {
+    if (_isRunning) return;
+
+    _isRunning = true;
+    _errorMessage = null;
+    _lastSavedPath = null;
+    notifyListeners();
+
+    try {
+      final diagnostics = await _rawCaptureService.getCameraDiagnostics();
+      if (diagnostics == null) {
+        _errorMessage = 'カメラ診断情報を取得できませんでした';
+        _isRunning = false;
+        notifyListeners();
+        return;
+      }
+
+      final savedPath = await _fileService.saveDiagnosticsJson(diagnostics);
+      await _rawCaptureService.scanFile(savedPath);
+
+      _lastSavedPath = savedPath;
+    } catch (e) {
+      _errorMessage = '診断の実行に失敗しました: $e';
+    }
+
+    _isRunning = false;
+    notifyListeners();
+  }
+}
diff --git a/lib/services/file_service.dart b/lib/services/file_service.dart
index 1f9765a..37b0d9f 100644
--- a/lib/services/file_service.dart
+++ b/lib/services/file_service.dart
@@ -1,3 +1,4 @@
+import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';
 
@@ -52,6 +53,36 @@
     return '${baseName}_$suffix.png';
   }
 
+  /// カメラ診断情報を JSON ファイルとして保存する．
+  ///
+  /// ファイル名: `camera_diagnostics_YYYYMMDD_HHmmss.json`
+  /// 保存先: `/storage/emulated/0/Pictures/MiniTIAS`
+  /// 戻り値は保存したファイルのフルパス．
+  Future<String> saveDiagnosticsJson(Map<String, dynamic> diagnostics) async {
+    final directory = Directory(_basePath);
+    if (!await directory.exists()) {
+      await directory.create(recursive: true);
+    }
+
+    final now = DateTime.now();
+    final timestamp =
+        '${now.year}'
+        '${now.month.toString().padLeft(2, '0')}'
+        '${now.day.toString().padLeft(2, '0')}'
+        '_'
+        '${now.hour.toString().padLeft(2, '0')}'
+        '${now.minute.toString().padLeft(2, '0')}'
+        '${now.second.toString().padLeft(2, '0')}';
+
+    final fileName = 'camera_diagnostics_$timestamp.json';
+    final filePath = '$_basePath/$fileName';
+
+    const encoder = JsonEncoder.withIndent('  ');
+    await File(filePath).writeAsString(encoder.convert(diagnostics));
+
+    return filePath;
+  }
+
   /// テスト用: タイムスタンプとファイル名一覧からファイル名を生成する．
   static String generateFileNameSync(
     String timestamp,
diff --git a/lib/services/raw_capture_service.dart b/lib/services/raw_capture_service.dart
index 9614251..e19e1cf 100644
--- a/lib/services/raw_capture_service.dart
+++ b/lib/services/raw_capture_service.dart
@@ -51,6 +51,17 @@
     return result;
   }
 
+  /// フロントカメラの Camera2 API 能力を診断情報として取得する．
+  ///
+  /// 戻り値はカメラの各種パラメータを含む Map．取得できない場合は null を返す．
+  Future<Map<String, dynamic>?> getCameraDiagnostics() async {
+    final result = await _channel.invokeMethod<Map<dynamic, dynamic>>(
+      'getCameraDiagnostics',
+    );
+    if (result == null) return null;
+    return result.cast<String, dynamic>();
+  }
+
   /// MediaStore にファイルを登録し，PC から MTP で見えるようにする．
   Future<void> scanFile(String path) async {
     await _channel.invokeMethod('scanFile', {'path': path});