An image forming apparatus includes a power supply board, a driver board, and an engine control board. The driver board includes a plurality of switching elements each configured to supply and shut off a power supply for each of a plurality of distributed power supply voltages supplied from the power supply board. The plurality of switching elements includes a first switching element, to which the power supply voltage is to be applied from the power supply board, and a second switching element, to which the power supply voltage output from the first switching element is to be applied in a distributed manner. The engine control board is configured to performs failure diagnosis of the first switching element when the image forming apparatus is activated, and performs failure diagnosis of the second switching element in a case where an abnormality has occurred in any one of a plurality of loads.