PURPOSE: To compensate an oscillating frequency with high accuracy, by turning on a switch means by a single pulse compensating signal and connecting once a frequency compensating capacitor and an oscillating circuit within a prescribed period.

CONSTITUTION: When a preset timing signal Ps is applied to down-counters 21, 22 and an FF24, the counters 21, 22 preset the content of a numeric data D and the FF24 is set. Thus, a single pulse compensating signal Pc' from an output terminal Q of the FF24 goes to logical 1. When the content of a data, for example, is preset to the counters 21, 22, a clock signal 2 counts down the counter 21 and when the pulse signal 2 is inputted by three pulses, a borrow signal PB1 is outputted from a terminal B of the counter 21 and the counter 22 is counted down by 1. When the count value of the counter 22 reaches 0 by similar repetition, the signal Pc' goes to logical D. When this signal Pc' is applied to a transmission gate so as to control on/off, the oscillating frequency is compensated accurately.