To enhance heat insulation and heat resistance of a heat insulation wall by constructing such a heat insulation wall by laminating a high temperature heat insulation material and a low temperature heat insulation material to each other in a direction of wall thickness and arranging the high temperature heat insulation material inside the heat insulation wall and the low temperature heat insulation material outside the heat insulation wall.

A heat insulation wall 1 comprises a high temperature insulation material 1a and a low temperature insulation material 1b which are laminated in a direction of wall thickness. The high temperature heat insulation material 1a is made of a soft heat insulation material 1b such as rock wool or glass wool, while the low temperature heat insulation material is made of a hard insulation material such as foamed urethane. The respective heat insulation materials 1a, 1b which are laminated to each other are accommodated between an inner box 1c and an outer box 1d, wherein the high temperature heat insulation material 1a is disposed at the side of inner box 1c while the low temperature heat insulation material 1b is disposed at the side of the outer box 1d. Due to such a construction, the heat insulation wall 1 can enhance its heat resistance and heat insulation thus preventing the deformation and deterioration of the heat insulation wall 1 and the increase of thermal loss of the heat insulation wall 1.