In order to suppress distortion in part of a waveform for a sinusoidal voltage generated by one of a pair of serially connected switch elements effectively turning on during an on/off deadtime in a circuit of a type provided with an on/off deadtime for the pair of switching elements, the power conditioner of the present invention comprises a first and second group including two switching elements each connected in inverse-parallel and in series. The power conditioner alternately turns on and off both switching elements in the first group at a prescribed chopping frequency and alternately turns on and off both switching elements in the second group at a PWM frequency higher than the chopping frequency. In addition, if control is performed with a deadtime provided in the on/off timing for both switch elements in each group, the power conditioner adjusts and controls the on/off duty for the second group switching elements to correspond to the effective on drive in one switching element by each diode during the dead time for each switching element in the first group.
