PURPOSE: To accurately and easily set time, by assembling two stages of inverters having a suitable ratio between the 1st capacitor and the inverter input terminal and increasing the voltage of the 1st capacitor.

CONSTITUTION: A potential change of a capaitor CL is received at an offset circuit 20 consisting of two stages of inverters comprising transistors Q8∼Q11. Then, taking around 1V of the threshold voltage of an output inverter and a linear region of discharge characteristic of a charge pump up to about 2V into consideration, the timer set time accuracy can be increased by using this region only. Thus, the inverting amplification of the inverter is applied, the offset amplifier consisting of the two stages of the inverters is constituted without losing the logic and the ratio of the inverters is set to a suitable value, allowing to easily correct the deviation from the threshold value of the output inverter.