To provide an IC socket in which IC devices are used in several overlapped layers by a simple constitution.

A first IC socket 26 has a socket main body 28 and a terminal 40 for the device to be overlapped on other members. This socket main body 28 has a member connecting part 32 and a wiring region part 44. At the member connecting part 32, the terminal 40 for the device connected to the respective terminals 14a of the IC device 12a at which a plurality of terminals including a chip select terminal are installed, and at least one expanded terminal 42 are installed. At the wiring region part 44, a wiring pattern 46 to connect the terminal 40a for the device corresponding to the chip select terminal and the extension terminal 42 is installed. The IC device 12a is exclusively used from the other IC devices because a chip select signal is sent via this wiring pattern 46 and the expanded terminal 42.