A charger for an electric power tool includes a charging unit for charging a secondary battery detachably attached to the charger; a notification unit for notifying an operation state of the charging unit by using a combination of a turn-on and turn-off of the notification unit; a brightness reducing unit for reducing a light brightness of the notification unit; and a controller for controlling the notification unit and the brightness reducing unit. If an operation state of the charging unit satisfies a specific condition, the controller controls the brightness reducing unit to reduce the light brightness of the notification unit.