An angular velocity sensor includes a piezoelectric body, a drive circuit, and a detection circuit. The piezoelectric body includes a pair of frames, a pair of drive arms, and a pair of detection arms. The pair of frames face each other in a y-axis direction in an orthogonal coordinate system xyz. The pair of drive arms are respectively laid bridging the pair of frames and face each other in an x-axis direction. The pair of detection arms extend from the pair of frames in the y-axis direction at positions between the pair of drive arms in the x-axis direction. The drive circuit applies voltages of mutually reverse phases to the pair of drive arms so that the drive arms vibrate bending to mutually reverse sides in the x-axis direction. The detection circuit detects signals generated due to the bending deformations of the pair of detection arms in a z-axis direction.