A power supply control circuit is connected to and controls a system power supply IC. The system power supply IC has multiple power supply circuits and is capable of outputting multiple power supply voltages. The system power supply IC activates the multiple power supply circuits at one time using a common enable signal. The power supply control circuit includes a gate circuit and a first switch unit. The gate circuit generates the common enable signal based on a control signal and a selection signal. The control signal is output from a control device during a usual operation. The selection signal is a signal that selects one of the multiple power supply circuits which is required to output the power supply voltage. The first switch unit is driven by a power-on signal during system activation, and switches on or off the selection signal input to the gate circuit.