PURPOSE: To form an efficient ratching type relay in a simple structure by making the leading of phase of the high-frequency voltage applied to a pair of piezo-electric elements inverse at the ON time and at the OFF time of the input signal, and applying the high-frequency voltage only for a specific time.

CONSTITUTION: To an input signal ON, amplifiers 25A and 25B are operated for a specific time, making a vibrator 1 generate circular or oval movement, a card 4 is moved to fixed contacts 6 side at the opposite side, and movable contacts 5 are also moved. And at the time when the contact pressure is maintained, the amplifiers 25A and 25B are turned off. In this case, the card 4 maintains a contact pressure by the static friction between the vibrator 1, and stops at the position. And when the input signal is turned off, the amplifiers 25A and 25B consisting of a pair of piezo-electric elements are operated in the same manner. Since the phase of the output of the amplifier 25B is shifted 180° from the phase in the ON time, the card 4 is moved in the opposite direction from that in the ON time, and carries out the operation exactly same as in the ON time. In such a way, the relay to operate the ratching to the simple ON and OFF input signals can be formed.