Provided is an electric connector, including: a housing placed on a circuit board and including a receiving concave portion formed by a substantially square-cylindrical-shaped inner wall surface and receiving a mating connector, and a center convex portion disposed between a pair of opposed walls forming the receiving concave portion; a plurality of terminals accommodated in a plurality of terminal grooves formed in each of the pair of the opposed walls; and a ground metal fitting connecting with a plate-shaped ground plate included in the mating connector, wherein the housing includes a space accommodating the ground metal fitting, where the space is disposed in the central area between the pair of the opposed walls and extends in the arrangement direction of the terminals, the upper part of the space communicates with an opening formed in the center convex portion, and receives the mating ground plate.