The IC socket assembly includes the heat sink for abutting the upper surface of an IC package to dissipate heat generated thereby, and a fixing member for fixing the heat sink to the housing. The fixing member includes: a frame, mounted on a surface of the circuit board, on which the housing is mounted; a back plate, mounted on the opposite surface of the circuit board, having engaging arms, which are inserted through apertures of the circuit board and engage the frame; a pair of loading beams, fixed to the engaging arms; and a pair of levers, axially supported by the loading beams, for urging the heat sink toward the housing.