To provide an IC socket capable of connecting a BGA-type IC and freely designing the number of through-holes, locations, and spacing of a mounted wiring board and attaining low height of a socket, and to provide a mounting structure thereof.

The IC socket includes a laminated board 2 for mounting the IC 10, a power source route collective circuit 3, a grand route collective circuit 4. The collective circuit 3 has a plurality of lands 31, a plurality of through-holes 33, a power source pattern 35, a collective through-hole 36, and a collective terminal 38, and the collective circuit 4 has a plurality of lands 41, a plurality of through-holes 42, a grand pattern 45, and a collective through-hole 46, and a collective terminal 48. Namely, a plurality of power source terminals 11 of the IC 10 connected to the lands 31 are collected to the power source collective terminal 38, and a plurality of grand terminals 12 connected to the lands 41 are collected to the grand collective terminal 48.