PURPOSE: To extend a service life by reducing power consumption by eliminating a wasteful boosting operation when a power supply voltage is highly fluctuated in a boosting circuit applied to an output circuit, etc., and which boosts an output signal of high level to the one of full Vcc level to prevent the output signal of high level from being lowered by the threshold value of a transistor.

CONSTITUTION: This circuit is equipped with a boosting decision circuit which outputs a boosting enable signal () representing whether or not a control voltage of high level applied to the gate of the transistor 7 which generates an output voltage should be boosted by the charge voltage of a capacitor 5 connected to the gate corresponding to the power supply voltage Vcc, and also, the circuit is equipped with a HAND circuit 26 setting the boosting enable signal () as input and which supplies the voltage to the other terminal of the capacitor 5 via an inverter 4, and prevents the boosting of the control voltage of high level by setting the other terminal of the capacitor 5 at a low level by the output of the HAND circuit 26 in accordance with the boosting enable signal ().