An AC to DC converter is provided with: a rectifier circuit that rectifies an AC voltage generated by an AC voltage source; and a plurality of switching units that collectively receive an output voltage of the rectifier circuit through an inductor, and that are connected in series at an input side, each of the switching units having a semiconductor switching device, a diode, and a capacitor, and performing ON/OFF switching of the semiconductor switching device provided therein to step up a voltage received from the rectifier circuit, each of the switching units supplying the stepped-up voltage to the capacitor through the diode so that a resulting DC across the capacitor can be provided, as a DC output voltage of the switching unit, to a respective load to be connected to terminals of the capacitor.