PURPOSE: To enable ICs of different terminal patterns and an emulator system to be mounted on the same IC socket.

CONSTITUTION: This IC adapter has a first alignment portion 1A in which first terminals 1a are aligned in the same pattern as the terminals of a so-called QFP type IC (not shown) so that the first terminals can be mounted on an IC socket 5 placed on a printed board 3a, and a second alignment portion 1B in which second terminals 1b electrically connected to the respective first terminals 1a are aligned so that the second terminals can be connected to an emulator system 4 whose pattern is different from that of the first terminals 1a. To debug an initial program when developing a microcomputer-applied product and the like, the first alignment portion 1A is mounted on the IC socket 5 with the emulator system 4 being connected to the second alignment portion 1B, so as to make evaluation using the emulator system 4 as to whether the product is operating as programmed, and ICs for mass production can also be mounted on the IC socket 5 thereafter.