Socket terminals include flat bar-like connection pieces that are in conductive contact with plug terminals, and the plug terminals include fork-shaped terminal portions that are in conductive contact with the socket terminals through the flat bar-like connection pieces. Plate surfaces of the plug terminals extend in a height direction and are fixed to a plug housing. Furthermore, fork-shaped terminal portions include contact recesses having openings in plate edges on a socket terminal insertion side. Contact projections of the contact recesses hold the flat bar-like connection pieces of the socket terminals that have been inserted through the openings in between in a direction (an up-down direction) that extends along the plate surfaces of the plug terminals.