An IC socket (11) comprises contact pins (14) disposed in the socket body (13) to be disjunctive to terminals of the IC package (12), an opening and closing body (19A,19B) rotatably provided in the socket body (13), the opening and closing body (19A,19B) having a pressing member (23a,23b) for pressing a top surface of the IC package (12) accommodated on an accommodating surface portion (16d) of the socket body (13); and an operating member (20) for opening and closing the opening and closing body (19A,19B) disposed up and down movably with respect to the socket body (13). A first opening and closing body (19A) having a heat sink (23a) for pressing an entire of the top surface of the IC package (12) and a second opening and closing body (19B) having a block (23b) for pressing the heat sink (23a) are disposed at different positions mutually.