The present invention provides a power device including a converter part (2) for converting an AC voltage to a DC voltage; an inverter part (3) for converting the DC voltage outputted from the converter part (2) to the AC voltage; and a transformer (4) having an inductance forming a series resonance circuit together with an electrostatic capacity of a load (20) to boost the AC voltage outputted from the inverter part (3). In the power device, an inductance (7) is connected to the output part of the inverter part (3) in parallel with the transformer (4). Thus, in a discharge part 6 provided in the load (20), since when a discharge is not generated, a recovery current is not supplied to a circulating current diode in the inverter part (3), or the quantity of the recovery current is reduced, the heat generation of the circulating current diode can be suppressed without increasing the number of elements of the circulating current diode.