To provide a heat radiation structure of ICs arranged on a board which can absorb a strain if a strain occurs on the board or bottom chassis.

The back of a board 1 is attached to a bottom chassis 2, an IC 4 arranged on the back of the board 1 is held by the bottom chassis 2 via a heat sink sheet 6, a heat sink 7 is installed on the lower side of the heat sink sheet 6 arranged on a lower face of the IC 4, a plurality of long screws 8 are inserted into the bottom chassis 2 from its lower face to the heat sink 7, edges of the plurality of long screws 8 are butted against a lower face of the heat sink 7, a positioning recess 7b is formed on the lower face of the heat sink 7 so as to insert the edge of the long screw 8 thereinto, a spring washer 10 is arranged between a head 8a of the long screw 8 and the bottom chassis 2, and heat generating in the IC 4 is radiated by the heat sink sheet 6 and the heat sink 7.