diff --git a/src/app/Livewire/DocumentEditor.php b/src/app/Livewire/DocumentEditor.php
index cf3623e..cc8ccfc 100644
--- a/src/app/Livewire/DocumentEditor.php
+++ b/src/app/Livewire/DocumentEditor.php
@@ -18,6 +18,8 @@ class DocumentEditor extends Component
     public function mount(?Document $document = null)
     {
         if ($document) {
+            $this->authorize('update', $document);
+
             $this->document = $document;
             $this->title = $document->title;
             $this->content = $document->content;
@@ -40,6 +42,8 @@ public function save(DocumentService $documentService)
 
         try {
             if ($this->isEditMode && $this->document) {
+                $this->authorize('update', $this->document);
+
                 $this->document = $documentService->updateDocument(
                     $this->document,
                     $this->title,
@@ -71,6 +75,8 @@ public function delete(DocumentService $documentService)
             return;
         }
 
+        $this->authorize('delete', $this->document);
+
         try {
             $documentService->deleteDocument($this->document);
             session()->flash('message', 'Document deleted successfully!');
diff --git a/src/app/Policies/DocumentPolicy.php b/src/app/Policies/DocumentPolicy.php
new file mode 100644
index 0000000..0d2728b
--- /dev/null
+++ b/src/app/Policies/DocumentPolicy.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Policies;
+
+use App\Models\Document;
+use App\Models\User;
+
+class DocumentPolicy
+{
+    public function before(User $user): ?bool
+    {
+        return $user->isAdmin() ? true : null;
+    }
+
+    public function view(User $user, Document $document): bool
+    {
+        return true;
+    }
+
+    public function create(User $user): bool
+    {
+        return true;
+    }
+
+    public function update(User $user, Document $document): bool
+    {
+        return $document->created_by === $user->id;
+    }
+
+    public function delete(User $user, Document $document): bool
+    {
+        return $document->created_by === $user->id;
+    }
+}
diff --git a/src/resources/views/livewire/document-viewer.blade.php b/src/resources/views/livewire/document-viewer.blade.php
index 9e9b0df..b3eafd1 100644
--- a/src/resources/views/livewire/document-viewer.blade.php
+++ b/src/resources/views/livewire/document-viewer.blade.php
@@ -6,7 +6,7 @@
                 {{ $document->title }}
             </h1>
 
-            @auth
+            @can('update', $document)
                 <a
                     href="{{ route('documents.edit', $document) }}"
                     class="inline-flex items-center justify-center px-3 sm:px-4 py-2 bg-indigo-600 text-white text-sm font-medium rounded-md hover:bg-indigo-700 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-indigo-500 whitespace-nowrap"
@@ -16,7 +16,7 @@ class="inline-flex items-center justify-center px-3 sm:px-4 py-2 bg-indigo-600 t
                     </svg>
                     {{ __('messages.documents.edit') }}
                 </a>
-            @endauth
+            @endcan
         </div>
 
         <div class="flex flex-col sm:flex-row sm:items-center text-xs sm:text-sm text-gray-500 gap-2 sm:gap-4">
diff --git a/src/routes/auth.php b/src/routes/auth.php
index 3926ecf..efc3763 100644
--- a/src/routes/auth.php
+++ b/src/routes/auth.php
@@ -7,16 +7,10 @@
 use App\Http\Controllers\Auth\NewPasswordController;
 use App\Http\Controllers\Auth\PasswordController;
 use App\Http\Controllers\Auth\PasswordResetLinkController;
-use App\Http\Controllers\Auth\RegisteredUserController;
 use App\Http\Controllers\Auth\VerifyEmailController;
 use Illuminate\Support\Facades\Route;
 
 Route::middleware('guest')->group(function () {
-    Route::get('register', [RegisteredUserController::class, 'create'])
-        ->name('register');
-
-    Route::post('register', [RegisteredUserController::class, 'store']);
-
     Route::get('login', [AuthenticatedSessionController::class, 'create'])
         ->name('login');
 
diff --git a/src/routes/web.php b/src/routes/web.php
index afdbd37..ce6f662 100644
--- a/src/routes/web.php
+++ b/src/routes/web.php
@@ -44,7 +44,9 @@
     // 認証が必要なルート（より具体的なルートを先に定義）
     Route::middleware('auth')->group(function () {
         Route::get('/create', DocumentEditor::class)->name('create');
-        Route::get('/{document}/edit', DocumentEditor::class)->name('edit');
+        Route::get('/{document}/edit', DocumentEditor::class)
+            ->middleware('can:update,document')
+            ->name('edit');
     });
 
     // 公開ルート（動的ルートは最後に）