To make it possible to enhance the heat insulation and to easily disassemble components regarding the easy reuse in the case of disassembling by combining the space field with foamed polystyrene among rear wall, upper wall, lower wall and sidewalls and layer element for shielding infrared rays to form a vessel compartment room.

Rear wall 2, upper wall 3, lower wall 4 and two sidewalls 5 having composite structure for forming outer sheet 6 and inner sheet 7 of hard material so that the thicknesses of the sheets 65, 7 are substantially thinner than the thickness of the space 8 between the sheets 6 and 7. The space 8 is fully filled with foamed polystyrene. At least one of the walls 3, 4, and 5 has a sheet 9 for freely containing a layer element 10 for shielding infrared rays. A vessel compartment room 1 is formed of the space 8 and element 10. Thus, high heat insulation is obtained, and the room 1 for a refrigerator or a deep freezer which can be easily disassembled to the components regarding to facilitate the reuse can be obtained.