Abstract: A system that provides an accurate frequency generating source, avoids mode coupling of the quartz vibrator, and has a high production efficiency. A high frequency amplifying circuit uses a bridge circuit as part of a feed back circuit, and a quartz vibrator is inserted in a branch side connecting the CR-circuit. The oscillation frequency is less than the serial resonance frequency of the quartz vibrator. The vibration energy is enclosed between the electrodes which prevents energy scattering to a blank edge by the oscillating quartz vibrator in a shear slipping mode with a lower frequency than the serial resonating frequency. Also, occurrence of the unnecessary shear coupling mode is restricted.