An electrical connector contains a plurality of contacts, a first ground plate and a second ground plate facing the plurality of contacts and arranged so as to be separated from each other in a ground plane parallel to the at least one plane in which the plurality of contacts are arranged and an insulator for holding the plurality of contacts, the first ground plate and the second ground plate in a state that the plurality of contacts, the first ground plate and the second ground plate are insulated from each other. Both of the first ground plate and the second ground plate include an extending portion extending from one of the first ground plate and the second ground plate toward the other one of the first ground plate and the second ground plate in the ground plane.