The present invention provides an angular velocity sensor in which higher sensitivity for sensors is available even with a smaller base portion. The angular velocity sensor includes a fixed portion fixed to the top surface of a sensor element supporting portion of a casing, an upper detection arm and a lower detection arm, each of them being connected to the fixed portion on sides opposite to each other and extending along a plane parallel to the top surface of the sensor element supporting portion, and a pair of upper vibration arms connected to the fixed portion in such a manner as to form a pair of arms with the upper detection arm in between and extending in a direction parallel to the extending direction of the upper detection arm.