To reduce the expense for a single-phase inverter device and reduce power consumption of the inverter device.

Since paired semiconductor switching elements 41 and 44 connected in series with each other between a power source 1 and a load 2 and operating synchronously to each other are conducted one after another, the loss of a single-phase inverter circuit 4 can be reduced remarkably. In addition, since the switching elements 41 and 44 are turned off one after another, the loss of the inverter circuit 4 can also be reduced remarkably. Moreover, since the switching elements 41 and 44 which are connected in series with each other and conducted in an overlapping state are respectively constituted of elements with a high breakdown voltage and a low breakdown voltage and the power supply to a reactance load is interrupted by actuating the element with high breakdown voltage prior to the element with low breakdown voltage, the economic effect and efficiency of a single-phase inverter device can be improved.