PURPOSE: To decrease the dispersion in the oscillating frequency of an oscillation circuit subject to temperature compensation by combining crystal vibrators divided from each frequency temperature characteristic with semiconductor elements provided with storage kinds corresponding to a frequency temperature deviation of the crystal vibrator.

CONSTITUTION: The frequency temperature characteristic of crystal vibrators 101 is measured and they are divided from each frequency temperature deviation. A semiconductor element 102 is used to store data corresponding to the kind of the frequency temperature deviation divided in this way. Then both components corresponding to each other are combined to form a crystal oscillator 100. The address of a memory circuit 112 receiving the output of a temperature detection circuit 114 is designated corresponding to the ambient temperature. The circuit 112 whose address is designated sends data corresponding to the temperature deviation to the decoder circuit 111 as memory information 150. The circuit 111 obtains the information 150 to select each switch 131 of a switched capacitor circuit 110 to be in the open state or the closed state. As a result, the oscillating frequency of the crystal oscillation circuit 103 is changed. When the ambient temperature changes, the address is changed and the oscillating frequency is changed.