Vibrator, resonator using the same and electromechanical filter using the same

A resonator comprising:

• a single-crystal substrate;
• a cavity formed in a back surface of the single-crystal substrate;
• a beam type vibrator formed so that at least one end of the vibrator is supported by a support part of the single-crystal substrate within a space between a front surface of the single-crystal substrate and a bottom surface of the cavity;
• and
• an electrode which applies excitation force of electrostatic force to the beam type vibrator,
• wherein the single-crystal substrate is a silicon substrate;
• wherein a cross section shape of the beam type vibrator is a triangular shape or a trapezoidal shape surrounded by crystal planes of {100} and {111};
• and
• wherein a thickness of the vibrator is thinner than that of the support part, and the support part is axisymmetrical with respect to a length direction of a beam of the vibrator.