A semiconductor device equipped with: a power supply circuit that contains multiple power supply blocks mutually having input/output relationships; a power supply control unit that outputs control signals to each of the power supply blocks indicating On/Off; a fault detection unit; and a sequencer. When the fault detection unit detects that any of the control signals indicates Off during startup of the power supply circuit, the sequencer moves to a prescribed shutdown sequence mode, and the power supply control unit performs a shutdown sequence in which the control signals are output so as to turn off the power supply blocks in a prescribed order.