PURPOSE: To prevent the generation of a through current from a positive power supply to a negative power supply and to reduce power consumption by controlling a driving transistor(TR) in an output stage so as to turn off the TR at a data changing point.

CONSTITUTION: When an input terminal 1 is '0', the output of an inverter circuit 2 is turned to '1', the output of a 2-input NOR circuit 3 is turned to '0', an n-channel type MOS TR 5 is turned off, the output of a 2-input NOR circuit 4 is turned to '1', an n-channel MOS TR 6 is turned on, and a '0' signal is outputted to an output terminal 7. Thereby, both the TRs 5, 6 are not simultaneously turned on. Since a through current does not flow through the output stage TR, power consumption can be reduced.