PURPOSE: To obtain an optical vibrator sensor by which a temperature, a pressure and the like can be measured with high accuracy without being affected by a noise.

CONSTITUTION: A vibrator 1 which is composed of a cantilever 41 and of a both-ends-fixed beam 42 and a signal processing part 3 are connected by an optical fiber 2. The optical fiber 2 is formed in such a way that an optical fiber 21 for interference measurement is arranged in the central part and that an optical fiber 22 for optical-pulse supply is arranged and installed in its circumference on the same axis. Optical pulses are sent to the vibrator 1 via the optical fiber 22 from a laser diode 32 inside the signal processing part 3, and the vibrator 1 is vibrated by an optical and thermal action. In addition, a laser beam for interference measurement is sent to the vibrator 1 via the optical fiber 21 from a laser diode 31, the number of vibrations of the vibrator 1 is measured by using interference light obtained by its reflected light, and a pressure is computed.