To diffuse heat generated from an electric appliance and/or to insulate sound generated from the electric appliance.

In this housing unit mounting structure for fixing a housing unit 1 into a recessed part 31 provided in a wall 29, the housing unit 1 is provided with a panel 3 formed to mount a large-sized thin television 27, on the back face side, and the panel 3 has a heat diffusion part 5 for diffusing heat generated from the large-sized thin television 27, and a sound insulating part 9 for insulating sound generated from the large-sized thin television 27. A space 32 with a clearance d is provided in the wall positioned behind the recessed part 31. The panel 3 is further provided with a rail 11a provided horizontally on the surface side to fasten the large-sized thin television 27. The storage unit 1 is provided integrally with a counter 22.