A socket for an electrical part comprises a socket body and a contact pin through which an electrical part having a terminal and a printed circuit board are electrically connected. The socket body is provided with a lower plate to be mounted to the printed circuit board and an upper plate which is disposed above the lower plate and on which the electrical part is mounted. The upper plate is exchanged with one having a seating portion of different height. A contact portion of the contact pin is also exchangeable with one having different shape or type.