To provide a flat pack IC socket enabled to correspond with the combination of different kind of IC packages, which can be tested with quick operation speed.

The flat pack IC socket comprises a base plate having two sets of contact rows symmetrically arranged at left side and right side, and a pressing board having two sets of pressing pads at its front side and back side, which hold the leads of IC package by pressing against the contact rows. The two sets of contact rows and the two sets of pressing pads might correspond either with different kind of IC packages or with same kind of IC packages. Further, two sets of pressing pads might be formed to a rotation free pressing member formed to a window of the pressing plate.