To provide a socket right fit for an IC, in which a number of bumps are arranged at small intervals in a lattice shape.

A base block 25 is disposed on the side of one surface of a printed circuit board 21 on the one surface, of which a plurality of contact electrodes 22 are formed at the same intervals as arrangement intervals of IC bumps and on the other surface, of which terminal electrodes 23 connected with those contact electrodes 22 respectively are formed at expanded intervals. A plurality of pass-through holes 31, respectively confronting the contact electrodes 22 are formed in a bottom surface of a recessed part 29 of the base block 25, and contact parts with the IC bumps are constituted by disposing coil-shaped contacts 33 in these pass-through holes 31.