To prevent a conductive end terminal and a conductive piece from being slackened due to heat generated by the conductive end terminal because of a long period of use, and also to provide a socket having comparatively good conductivity and safety.

The socket is equipped with an insulation body 62 and at least an end terminal and a conductive piece 63 set in the body. Among them, each end terminal is equipped with a central cylinder having a first terminal 611 and a second terminal 612, a first ring 613 having a first surface and a second surface, and a second ring 614 having a third surface and a fourth surface. With this, the end terminal is fixed to the body using the first ring and the second ring, then the conductive piece has a cavity to be fitted and mounted to the second terminal of each end terminal with, and also, makes electrical connection directly contacting with the second ring.