According to one embodiment, a sensor includes a base body, and a first sensor part. The first sensor part includes fixed and movable electrode members, and first and second support members. The fixed electrode member includes a fixed electrode fixed to the base body. The movable electrode member includes a movable electrode. The movable electrode member includes first and second movable portions, and a third movable portion between the first and second movable portions. The first support member is fixed to the base body and connected with the first movable portion. The second support member is fixed to the base body and connected with the second movable portion. The first and second support members support the movable electrode member to provide a first gap between the fixed and movable electrode members. The fixed electrode member includes first, second, and third fixed electrode portions facing the movable portion.