A plug body is adapted to be fitted into a socket body in a first direction, and formed with a groove extending in a second direction perpendicular to the first direction. Each of plug contacts has a first contact piece and a second contact piece opposing to each other with a gap therebetween. The plug contacts are arrayed such that the first contact piece and the second contact piece are disposed in the groove. Each of projections is extended from the first contact piece so as to oppose the second contact piece, and is formed with a slant face so that a thickness thereof is reduced toward a distal end thereof. The slant faces of the projections form V-shaped lines when the projections are viewed from the first direction.