diff --git a/voicevox_engine/app/routers/engine_info.py b/voicevox_engine/app/routers/engine_info.py
index d2894f706..4299e1581 100644
--- a/voicevox_engine/app/routers/engine_info.py
+++ b/voicevox_engine/app/routers/engine_info.py
@@ -1,13 +1,34 @@
 """エンジンの情報機能を提供する API Router"""
 
 import json
+from typing import Self
 
 from fastapi import APIRouter, HTTPException, Response
+from pydantic import BaseModel, Field
 
 from voicevox_engine import __version__
+from voicevox_engine.core.core_adapter import DeviceSupport
 from voicevox_engine.core.core_initializer import CoreManager
 from voicevox_engine.engine_manifest.EngineManifest import EngineManifest
-from voicevox_engine.model import SupportedDevicesInfo
+
+
+class SupportedDevicesInfo(BaseModel):
+    """
+    対応しているデバイスの情報
+    """
+
+    cpu: bool = Field(title="CPUに対応しているか")
+    cuda: bool = Field(title="CUDA(Nvidia GPU)に対応しているか")
+    dml: bool = Field(title="DirectML(Nvidia GPU/Radeon GPU等)に対応しているか")
+
+    @classmethod
+    def generate_from(cls, device_support: DeviceSupport) -> Self:
+        """`DeviceSupport` インスタンスからこのインスタンスを生成する。"""
+        return cls(
+            cpu=device_support.cpu,
+            cuda=device_support.cuda,
+            dml=device_support.dml,
+        )
 
 
 def generate_engine_info_router(
@@ -32,15 +53,12 @@ async def core_versions() -> Response:
     @router.get(
         "/supported_devices", response_model=SupportedDevicesInfo, tags=["その他"]
     )
-    def supported_devices(core_version: str | None = None) -> Response:
+    def supported_devices(core_version: str | None = None) -> SupportedDevicesInfo:
         """対応デバイスの一覧を取得します。"""
         supported_devices = core_manager.get_core(core_version).supported_devices
         if supported_devices is None:
             raise HTTPException(status_code=422, detail="非対応の機能です。")
-        return Response(
-            content=supported_devices,
-            media_type="application/json",
-        )
+        return SupportedDevicesInfo.generate_from(supported_devices)
 
     @router.get("/engine_manifest", response_model=EngineManifest, tags=["その他"])
     async def engine_manifest() -> EngineManifest:
diff --git a/voicevox_engine/core/core_adapter.py b/voicevox_engine/core/core_adapter.py
index ba3c24908..61981c089 100644
--- a/voicevox_engine/core/core_adapter.py
+++ b/voicevox_engine/core/core_adapter.py
@@ -1,4 +1,6 @@
+import json
 import threading
+from dataclasses import dataclass
 
 import numpy as np
 from numpy.typing import NDArray
@@ -7,6 +9,15 @@
 from .core_wrapper import CoreWrapper, OldCoreError
 
 
+@dataclass(frozen=True)
+class DeviceSupport:
+    """音声ライブラリのデバイス利用可否"""
+
+    cpu: bool
+    cuda: bool  # CUDA (Nvidia GPU)
+    dml: bool  # DirectML (Nvidia GPU/Radeon GPU等)
+
+
 class CoreAdapter:
     """
     コアのアダプター。
@@ -28,13 +39,19 @@ def speakers(self) -> str:
         return self.core.metas()
 
     @property
-    def supported_devices(self) -> str | None:
+    def supported_devices(self) -> DeviceSupport | None:
         """デバイスサポート情報（None: 情報無し）"""
         try:
-            supported_devices = self.core.supported_devices()
+            supported_devices = json.loads(self.core.supported_devices())
+            assert isinstance(supported_devices, dict)
+            device_support = DeviceSupport(
+                cpu=supported_devices["cpu"],
+                cuda=supported_devices["cuda"],
+                dml=supported_devices["dml"],
+            )
         except OldCoreError:
-            supported_devices = None
-        return supported_devices
+            device_support = None
+        return device_support
 
     def initialize_style_id_synthesis(
         self, style_id: StyleId, skip_reinit: bool
diff --git a/voicevox_engine/model.py b/voicevox_engine/model.py
index 2249b34bc..beb4b4098 100644
--- a/voicevox_engine/model.py
+++ b/voicevox_engine/model.py
@@ -326,16 +326,6 @@ class WordTypes(str, Enum):
     SUFFIX = "SUFFIX"
 
 
-class SupportedDevicesInfo(BaseModel):
-    """
-    対応しているデバイスの情報
-    """
-
-    cpu: bool = Field(title="CPUに対応しているか")
-    cuda: bool = Field(title="CUDA(Nvidia GPU)に対応しているか")
-    dml: bool = Field(title="DirectML(Nvidia GPU/Radeon GPU等)に対応しているか")
-
-
 class SupportedFeaturesInfo(BaseModel):
     """
     エンジンの機能の情報