Power supply control apparatus

A power supply control apparatus (2) includes: an output transistor (T1) coupled between a first power supply line and an output terminal (OUT), the output terminal (OUT) being configured to be coupled with a load (11); a protection transistor (MN8) coupled between a gate of the output transistor and a second power supply line; a negative voltage control unit (20) coupled between the first power supply line and the gate of the output transistor; a compensation transistor (MN7) bringing the second power supply line and the output terminal (OUT) into a conduction state when a counter electromotive voltage from the load is applied to the output terminal (OUT); and a back gate control circuit (18) that controls the second power supply line and a back gate of each of the compensation transistor (MN7) and the protection transistor (MN8) to be brought into a conduction state in a standby state when the polarity of the power supply is normal.