In a power conversion circuit in which a grounded capacitor is connected to a main circuit that converts power through operation of a semiconductor switching device, a control IC that supplies a drive signal to the semiconductor switching device generates a cancellation voltage for canceling out a conducted emission that develops across terminals of the grounded capacitor as a result of the operation of the semiconductor switching device by using the drive signal (gate signal) to control a charge/discharge current of a compensation capacitor in a compensation circuit that is externally connected to the main circuit.