PURPOSE: To reduce power consumption by turning on and off a transistor of a bridge circuit alternately in a pulse generation circuit to generate positive and negative pulse voltage alternately.

CONSTITUTION: An inverter is constituted of an oscillation circuit 1, a driving circuit 2, a pulse generating circuit 3 and a constant voltage circuit 5. When DC voltage V1 is applied to the oscillating circuit 1, oscillation is made with a frequency according to the time constant of a capacitor Cx and resistor R, and corrugated waveform voltage is outputted from the circuit 1. The corrugated waveform voltage is inputted into the driving circuit 2, from which two operating signals Vd1∼Vd2 with different operating points are outputted after a quiescent period. Those signals are inputted into each input terminal alternately, and accordingly, Tr1∼Tr2 and Tr3∼Tr4 of each opposite side of a bridge circuit 4 constituting the circuit 3 are turned on and off alternately. As a result, the DC voltage V2 is converted into positive and negative voltage having a pulse quiescent period, and is taken out from inter-output terminals.