A power supply control circuit comprises an output transistor which controls supply of electric power to a load and a gate driving circuit which generates control signals “a” and “b” for controlling on/off of the output transistor 32 based on an external input signal. A transistor 37 discharges a gate charge of the output transistor based on the control signals “a” and “b”, when turning off the output transistor. A transistor 39 discharges more slowly than the transistor. A diode is coupled to the transistor 37 in series and which cuts off a discharge path through the transistor 37 transistor and the diode when the gate voltage of the output transistor falls to a voltage level higher than the sum of the power supply voltage Vcc and a threshold voltage of the output transistor, at a time of turning off the output transistor.