A device has a plurality of power states. The device includes: a communication processor configured to communicate with a communication destination device connected via a cable; a confirmation-signal receiver configured to receive a connection confirmation signal that is transmitted if being connected to the communication destination device via the cable; a contoller configured to determine a power state depending on whether the confirmation-signal receiver receives the connection confirmation signal; and a power circuit configured to control supply of electric power to at least one of the communication processor and the contoller in accordance with the power state determined by the contoller.