A sense voltage obtained by feeding a sense current of an IGBT into a sense resistor is input to a comparator, and as the reference voltage of the comparator, a sense voltage immediately before the IGBT is turned off is held by a sample and hold circuit for each switching, and is then divided by a voltage dividing circuit and the divided voltage is input to the comparator. The comparator compares the sense voltage with the voltage based on the sense voltage immediately before the IGBT is turned off, and therefore the comparator may accurately detect the falling edge time of the sense voltage and is used for the control for dissolving the imbalance in current with respect to the other IGBTs connected in parallel.