A power supply device includes a plurality of DC voltage generating circuits that share a voltage control circuit controlling a voltage to be supplied to a voltage stabilizing capacitor. The voltage control circuit and the DC voltage generating circuits are controlled so that supplying voltage to the capacitor is stopped to stop output, that a first DC voltage generating circuit among the plurality of DC voltage generating circuits is driven for a predetermined time period and is then stopped, and that supplying voltage to the capacitor is started and also a second DC voltage generating circuit among the plurality of DC voltage generating circuits starts to be driven to output a positive bias, in order to sequentially perform a stop of output from the first DC voltage generating circuit and a start of output from the second DC voltage generating circuit. Accordingly, overshoot of an output voltage is prevented.