PURPOSE: To reduce support loss by adding an adjustment mechanism, which consists of an elastic material with one free end, to a part of the support mechanism of a piezo-electric plate in the piezo-vibrator of thickness vibration.

CONSTITUTION: Crystal plate 11 is fitted strongly to conductive support machanisms 41 and 41' consisting of elastic materials by conductive cements 31 and 31'. Simultaneously with fitting, electrodes 21 and 21' on the surface and the reverse face are connected electrically to terminals 51 and 51' of holder 61. Support mechanisms 42 and 42' are connected to terminals 51 and 51' and support mechanisms 41 and 41', and the whole of crystal plate 11 and mechanisms 41, 41', 42 and 42' constitutes one vibrator. Resistance R1 of the equivalent circuit of this overall vibrator can be set to a very small value by adjusting dimensions n1 or n2 of the support mechanism.