A fixed insulator includes a plurality of first fixing grooves disposed along an arrangement direction in which a plurality of contacts are arranged, and partition walls each disposed between two adjacent contacts. A movable insulator includes a plurality of second fixing grooves disposed along the arrangement direction. The contacts each include a first base portion supported by a corresponding one of the first fixing grooves, a second base portion supported by a corresponding one of the second fixing grooves, a first arm portion connected to the first base portion and disposed between two corresponding adjacent ones of the partition walls, and a second arm portion connected to the first arm portion and the second base portion. A largest width of the first arm portion is smaller than a largest width of the second arm portion.