PURPOSE: To provide a small size IC socket, by which observation of an input/ output waveform and input of an optional signal can be carried out without any additional modification on a base board.

CONSTITUTION: An observation terminal 4, whose one end part is exposed from the side face of a socket main body 1, is arranged inside the socket main body 1. The first clamping part 6, which elastically clamps the observation terminal 4 freely slidably in the arrow direction, is integrated in a lead terminal 5. The second clamping part 8, which elastically clamps the other end part of the observation terminal 4 freely slidably in the arrow direction, is integrated in a base board mounting terminal 3. When the observation terminal 4 is pulled out from the main body 1, the observation terminal 4 is released from the second clamping part 8, so that the lead terminal 5 and the base board mounting terminal 3 are electrically insulated from each other. When the observation terminal 4 is pushed into the socket main body 1, the lead terminal 5 and the base board mounting terminal 3 are electrically connected together via the observation terminal 4.