diff --git a/src/utr_usb_inventory_with_output_power.py b/src/utr_usb_inventory_with_output_power.py
index 3018961..be619c3 100644
--- a/src/utr_usb_inventory_with_output_power.py
+++ b/src/utr_usb_inventory_with_output_power.py
@@ -26,7 +26,7 @@
 import re
 import sys
 import time
-from typing import Optional
+from typing import Any, Optional
 
 import serial
 from serial.tools import list_ports
@@ -167,9 +167,28 @@ def _set_command_mode(ser: serial.Serial) -> None:
     raise RuntimeError("コマンドモード切替に失敗しました。")
 
 
+def _create_output_power_restore_state() -> dict[str, Any]:
+    """送信出力一時変更の復元状態を保持します。
+
+    plans:
+        変更用フレームと復元用フレームのセットです。
+    restore_required:
+        変更送信を試みたため、異常終了時に復元対象とみなす状態です。
+        ACK後の読み戻しで例外が発生しても復元できるようにします。
+    restore_done:
+        finallyで二重復元しないためのフラグです。
+    """
+    return {
+        "plans": None,
+        "restore_required": False,
+        "restore_done": False,
+    }
+
+
 def _offer_temporary_output_power_change(
     ser: serial.Serial,
     identified_model_key: str | None,
+    restore_state: dict[str, Any] | None = None,
 ) -> OutputPowerTemporaryChangePlans | None:
     """Inventory前に送信出力一時変更を提案し、変更した場合は復元計画を返します。"""
     current_setting = _read_current_output_power_setting(ser)
@@ -204,6 +223,10 @@ def _offer_temporary_output_power_change(
         print("送信出力は変更しません。")
         return None
 
+    if restore_state is not None:
+        restore_state["plans"] = plans
+        restore_state["restore_required"] = True
+
     _send_output_power_frame(ser, plans.change_plan.command_frame, "送信出力の一時変更")
     _read_current_output_power_setting(ser)
     return plans
@@ -212,19 +235,31 @@ def _offer_temporary_output_power_change(
 def _restore_temporary_output_power(
     ser: serial.Serial,
     plans: OutputPowerTemporaryChangePlans | None,
+    restore_state: dict[str, Any] | None = None,
 ) -> None:
     """一時変更した送信出力を元に戻します。"""
-    if plans is None:
+    effective_plans = plans
+    if restore_state is not None:
+        if restore_state.get("restore_done"):
+            return
+        if not restore_state.get("restore_required"):
+            return
+        effective_plans = effective_plans or restore_state.get("plans")
+
+    if effective_plans is None:
         return
 
     try:
-        _send_output_power_frame(ser, plans.restore_plan.command_frame, "送信出力の復元")
+        _send_output_power_frame(ser, effective_plans.restore_plan.command_frame, "送信出力の復元")
         _read_current_output_power_setting(ser)
     except Exception as exc:
         print("")
         print("送信出力の復元に失敗しました。")
         print("UTRRWManagerまたは再実行時の読み取りで、機器側の現在設定を確認してください。")
         print(f"復元エラー: {exc}")
+    finally:
+        if restore_state is not None:
+            restore_state["restore_done"] = True
 
 
 def _read_inventory_parameters(ser: serial.Serial) -> None:
@@ -384,6 +419,7 @@ def main() -> None:
     ser: serial.Serial | None = None
     antenna_selection: Optional[InventoryAntennaSelection] = None
     output_power_plans: OutputPowerTemporaryChangePlans | None = None
+    output_power_restore_state = _create_output_power_restore_state()
     total_iterations = 0
     total_read_time = 0.0
     total_read_count = 0
@@ -405,7 +441,11 @@ def main() -> None:
 
         rom_info, identified_model_key = _verify_usb_and_read_model_key(ser)
         _set_command_mode(ser)
-        output_power_plans = _offer_temporary_output_power_change(ser, identified_model_key)
+        output_power_plans = _offer_temporary_output_power_change(
+            ser,
+            identified_model_key,
+            restore_state=output_power_restore_state,
+        )
 
         read_and_print_pre_inventory_reader_settings(ser)
         _read_inventory_parameters(ser)
@@ -427,7 +467,11 @@ def main() -> None:
         print(f"エラー内容: {exc}")
     finally:
         if ser is not None:
-            _restore_temporary_output_power(ser, output_power_plans)
+            _restore_temporary_output_power(
+                ser,
+                output_power_plans,
+                restore_state=output_power_restore_state,
+            )
             finish_inventory_session(
                 ser,
                 antenna_selection,