A socket includes a substantially rectangular columnar socket body made of an insulating material and the socket body including a connection recess portion defined on one surface thereof. Side walls opposed to each other in a transverse direction and lead-out pathways formed in the side walls. The socket further includes a plurality of socket contact members arranged side by side within the connection recess portion along a longitudinal direction. One-end portions of the socket contact members extend through the lead-out pathways and protruding outwards beyond an outer surface of at least one of the side walls of the socket body. The socket body includes a depression portion formed on the side wall through which the socket contact members protrude and the depression portion being formed at least around the socket contact members.
