<p>A power supply device includes a main body, a cover member, a rechargeable battery, and an inverter device. The main body is configured of box-shape formed with an opening. The cover member is configured to open and close the opening. The rechargeable battery is accommodated in the main body. The inverter device is configured to be accommodated in the main body. The inverter device converts a direct voltage from the battery to an alternating voltage and outputs the alternating voltage.</p>