Oscillatory angular rate sensor

An oscillatory angular rate sensor unit includes a mount base and a sensor element installed on the mount base. The sensor element includes an oscillator which produces angular velocity-caused oscillations in a first direction when the sensor element experiences angular motion during self-excited oscillation of the oscillator in a second direction opposite the first direction. A resonant frequency of the sensor unit in the first direction is set to a value less than or equal to a reciprocal of square root of two times a difference between resonant frequencies of the oscillator in the first and second directions, thereby eliminating an error output caused by undesirable acceleration acting on the sensor unit.