Abstract: A plurality of spring housing holes are formed in a first surface of an insulation block of a socket connector, and contact insertion holes are formed in a second surface of the block in communication with the spring housing holes. In each spring housing hole, a coil spring is housed, and the insulation block holds a terminal connected to the corresponding coil spring. A plurality of plug contacts are arranged and embedded in an insulation body of a plug connector. When the plug contacts are inserted into the contact insertion holes, the plug contacts are inserted and engaged between coils of the coil springs to connect the plug contacts and springs electrically with each other.