An object is to provide an electromechanical filter which can define a vibration mode so that a vibrator can be excited only in a desired vibration mode, that is, a filter which can suppress any vibration mode other than a desired vibration mode. The electromechanical filter includes a first member for inputting a signal, a second member disposed at a predetermined distance from the first member so as to surround the first member and to be excited due to an electrostatic force caused by the signal input from the first member, and a third member disposed at a predetermined distance from the second member so as to surround the second member and to detect vibration of the second member. The second member is designed to receive an attractive force from the first member and the second member so as to be bound and regulated as to a vibration direction.