A thin film micromechanical resonator (resonator) having improved drive efficiency, a resonator gyro having improved sensitivity in detecting an angular velocity, and a navigation system and an automobile using the resonator gyro. The resonator includes a tuning fork structure made of a non-piezoelectric material, and a first electrode and a second electrode disposed respectively at the inner side and the outer side of the tuning fork arm. On the first and second electrodes, a first piezo film and a second piezo film are provided respectively, and a third electrode and a fourth are respectively provided electrode thereon. When an alternating voltage is applied to the third and fourth electrodes at the opposite phases each other, the tuning fork resonates in the direction perpendicular to the center line. The resonator gyro detects, at the sensing section which is formed of another electrodes and another piezo film, the Coriolis force generated in proportion to angular velocity given to the resonator.