Disclosed is a mobile X-ray apparatus that performs a stable operation even if a sudden voltage drop or momentary power interruption occurs during operation of a commercial AC power source. The mobile X-ray apparatus includes a plug 20 for connection to an external power source 100, a battery charged from the external power source 100 through the plug 20, a unit 30 that operates by being supplied with electricity from the commercial AC power source 100 connected through the plug 20, and a second circuit 29 including a rectifier 27 that supplies electricity to the unit 30 from the battery 24 if a voltage from the commercial AC power source 100 falls to or below a regulated value while the unit 30 is being operated by the electricity supply from the commercial AC power source 100.