A gyro sensor includes: a driving mass; a detection mass connected with the driving mass; a driving connection one end and the other end of which are connected with the driving mass and an anchor, respectively; an island connected with the anchor, and disposed with a clearance left between the island and the driving mass in such a manner as to be electrically connected with the driving mass; and a projection provided at least either on the surface of the driving mass opposed to the island, or on the surface of the island opposed to the driving mass. The driving unit includes a movable electrode unit connected with the driving mass, and a fixed electrode unit. The minimum distance between the driving mass and the island is longer than the driving amplitude of the driving mass and shorter than the maximum amplitude of the movable electrode unit.