An emitter interconnection connecting the emitter of a semiconductor switching element to a negative electrode is different in one or both of length and width from an emitter interconnection connecting the emitter of a semiconductor switching element to the negative electrode. At the time of switching, an induced electromotive force is generated at a gate control wire, or at a gate pattern, or at an emitter wire, by at least one of a current flowing through a positive electrode and a current flowing through the negative electrode, so as to reduce the difference between the emitter potential of the semiconductor switching element and the emitter potential of the semiconductor switching element caused by the difference.