Disclosed is a device for driving an inverter having a semiconductor switching element. A gate voltage calculating unit (20) calculates a surge voltage from the temperature, current, and DC-side voltage of each of IGBTs of the inverter and compares the surge voltage with the breakdown voltage of the element. The gate voltage calculating unit (20) commands a gate voltage control unit (22) to set a gate voltage higher than the normal value (reference value) in the case of judging that the difference between the element breakdown voltage and the surge voltage exceeds a predetermined threshold voltage and that a margin exists in the surge voltage. The voltage control unit (22) performs switching control of gates of the IGBTs according to the gate voltage command higher than the reference voltage to thereby reduce stationary losses of the IGBTs.