A power supply apparatus includes a first power factor correction circuit, a second power factor correction circuit and a control circuit that includes a first switching control unit that outputs a first switching signal for controlling a first switching element of the first power factor correction circuit generated in accordance with a detected result by an output voltage of the first power factor correction circuit and a current flowing through the first switching element, and a second switching control unit that outputs a second switching signal for controlling a second switching element of the second power factor correction circuit generated in accordance with a detected result by an output voltage of the second power factor correction circuit and a current flowing through the second switching element.