PURPOSE: To obtain a prescribed frequency independently of temperature, by compensating the error in accuracy due to aging of a quartz intself at the circuit side as well as temperature correction of a quartz oscillator for timepiece.

CONSTITUTION: As a main quartz oscillator, an oscillator with small temperature coefficient in frequency fm and lower top point temperature than room temperature is selected, and as a subquartz oscillator, an oscillator with lower top point temperature of temperature coefficient in frequency fs than that of the main auartz oscillator is selected. The ratio N of fm and fs increases monotonously with the temperature rise. Further, a function of gm=AN4+BN3+CN2+DN+E is determined, the A∼E are stored, the N is detected and the gm is calculated by the operation circuit. Thus, the temperature cahracteristics of the gm which changes timewise in temperature are obtained and the frequency dividing ratio of a variable frequency divider is made proportional to the gm, allowing to obtain a constant period independently of temperature.