A driving circuit outputs an output voltage as a driving signal to the gate of a semiconductor element based on a control signal given from an input circuit. The output voltage is at “H” (ON level) if it is determined by a power supply voltage VCC, and is at “L” (OFF level) if it is determined by a ground voltage GND. A reference power supply section includes a series connection of resistors. The reference power supply section obtains a voltage determined by dividing a potential difference between the power supply voltage VCC and the ground voltage GND by a predetermined dividing ratio (resistance ratio between the resistors) as a reference voltage. A buffer circuit applies an output voltage as a reference signal determined by the reference voltage to the source of the semiconductor element.