PURPOSE: To adjust or change the resonance frequency of a piezoelectric tuning fork vibrator simply by adhering a mass to both vibration parts formed as a tuning fork to both sides of a slit symmetrically in the center of the slit.

CONSTITUTION: Sets of mass 6a, 6b are adhered symmetrically to vibration parts 4a, 4b around a slit 3. This is because the waveform is split and the frequency is changed to the both when the mass is adhered to one side only. The characteristic of the resonance frequency shown in solid lines shows an example when a thermosetting epoxy resin as the mass 6a, 6b is applied in the thickness of nearly 20μm. The resonance frequency f1 is decreased more than f0 by nearly 4kHz as shown in figure. The resonance frequency of a piezoelectric tuning fork vibrator 1 is simply adjusted without change of the slit depth of the slit 3 and the thickness of the piezoelectric substrate 2 or the like by the addition of the mass 6a, 6b.