In some aspects of the invention, a number of semiconductor switches through which output current passes can be reduced between a direct current power source side, which is an input, and an alternating current output, thus achieving loss reduction, and enabling higher efficiency, price reduction, and miniaturization of a device. In some aspects, a direct current power source, formed of a series connection circuit of single power sources, which has three mutually different voltage levels including zero can be provided with first, second, third, and fourth arm pairs, each configured by connecting two arms formed of semiconductor switches in series, an alternating current switch configured by combining semiconductor switches. As such, a plurality of voltage levels can be to be selected from and output by an on and off control of these switch elements.