PURPOSE: To simultaneously compensate temperature compensation of plural crystal oscillation sections, to decrease the circuit scale and to attain high reliability and low power consumption by adopting the constitution that plural digital analog conversion sections and voltage controlled crystal oscillation sections are connected respectively to an output of a storage section.

CONSTITUTION: A temperature sending section 1 senses a change in the ambient temperature, a temperature voltage signal is outputted and the temperature voltage signal is converted into a digital quantity by an analog digital conversion section 2. The digital temperature signal is fed to a storage section 3. A data required to apply temperature compensation to crystal oscillation sections 7, 8, 9 such as frequency temperature characteristic of the crystal oscillators 7, 8, 9 is stored in the storage section 3 by using the digital temperature signal as the address. The output of the storage section 3 is fed to the crystal oscillation sections 7, 8, 9 as the analog temperature compensation voltage through the digital analog conversion sections 4, 5, 6.