PURPOSE: To suppress the generation of overshooting and undershooting due to overcurrents by inputting respective signal waveforms with a moderate change and a sharp change to individual MOSFETs.

CONSTITUTION: When an input is change from 'H' to 'L', an FET Mp1 in the 1st control circuit COT1 is turned on and the potential of a point A is 5 raised almost simultaneously with the trailing time of an input waveform. In the 2nd control circuit COT2, FETs Mp2, Mp3 are also turned on and the potential of a point B is moderately raised as compared with the point A. Thereby the undershooting phenomenon of an output waveform is reduced. When the input is turned from 'L' to 'H', the potential of the point B falls almost simultaneously with the leading time of the input waveform and the potential of the point A falls slowly falls in comparison with the point A. Thereby the overshooting phenomenon of the output waveform can be suppressed without allowing a sharp transient current to flow into a transistor(TR) Mp4.