Abstract: In order to reduce an induction problem, which might otherwise be caused by a higher-harmonic current leaking to the outside of an inverter device, with a simple construction, an inverter device casing and a heat receiving plate mounted thereon are insulated from each other, and the heat receiving plate and a filter capacitor in the power supply circuit are connected through a predetermined inductance. Since the higher harmonics current is bypassed to the filter capacitor through the resonance filter which is formed by of the electrostatic capacity in a switching element and the inductance, the induction problem can be reduced by simple construction.