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 for connection to a commercial AC power source, a battery charged from the commercial AC power source through the plug, a unit that operates by being supplied with electricity from the commercial AC power source connected through the plug, and a second circuit including a rectifier that supplies electricity to the unit from the battery if a voltage from the commercial AC power source falls to or below a regulated value while the unit is being operated by the electricity supply from the commercial AC power source.