To provide an inverter device, wherein the switching elements in an inversion circuit are protected through the operation of a protective circuit and damages to the protective circuit itself are prevented without making the overall circuitry complicated.

In a device 10, an insulated gate bipolar transistor(IGBT) 22 as protective circuit 13 is placed between a rectification circuit 11, which phase- controls a thyristor 15 and an inversion circuit 12 which switches a MOSFET 21 at high speed. As a result, even if the IGBT 22 is turned off to protect the MOSFET 21 in the inversion circuit 12 when an overcurrent is produced, the IGBT 22 also prevented form being damaged due to the overcurrent. Furthermore, since the constitution of the protective circuit 13 is simple, the circuitry of the entire high-frequency voltage-type inverter device 10 will not become complicated at all.