In a power converter provided with a group of semiconductor switches including at least one semiconductor switch and a DC terminal connected to the semiconductor switch group, a clamping circuit is connected to the semiconductor switch or the DC terminal. Alternatively a diode having a wide band gap is connected in parallel to a snubber diode or a snubber capacitor in a snubber circuit connected in parallel to the semiconductor switch. Thus, overvoltages and oscillating voltage applied to the semiconductor switch are suppressed.
