A power supply control apparatus controls power supply from a DC power source to a load by switching on or off a power supply FET. The current adjustment circuit adjusts the current flowing through the resistor circuit to a value obtained by dividing the voltage between the drain and the source of the power supply FET by the resistance value of the resistor circuit. A drive circuit switches off the power supply FET when a voltage across the detection resistor exceeds a predetermined voltage. The on-resistance value of the power supply FET fluctuates according on the ambient temperature of the power supply FET. The resistance value of the resistor circuit fluctuates in the same direction as the on-resistance value according to the ambient temperature of the power supply FET.