To provide an angular velocity sensor using a sensor element having an electrostatic capacity varied depending on an applied angular velocity, which has high detection precision with little dispersion of sensitivity and is manufacturable at a low cost.

This angular velocity sensor 50 comprises a sensor element 10 having an output end part 38 whose electrostatic capacity is varied depending on an applied angular velocity. An electrostatic capacity detecting circuit 52 consisting of an operational amplifier 54, a feedback resistance 56 and a reference voltage source 58 is connected to the output end 38 of the sensor element 10. The output end of the electrostatic capacity detecting circuit 52 for applying the voltage equal to the reference voltage source 58 to the output end 38 of the sensor element 10 as bias voltage by the imaginary short circuit of the operational amplifier 54 is connected to an AC amplifier 60, and further connected to a synchronous wave detecting circuit 62 and a low pass filter 64.