| 摘要 |
PROBLEM TO BE SOLVED: To constitute an inner face of an outer wrapping body with a material having a smaller coefficient of linear expansion than a material of an outer face, and to let a gap open between an outer face of a wall face and an inner face of heat-resistant vacuum heat insulating materials not formed to maintain heat insulating properties of a heating chamber.SOLUTION: A first member 11 disposed on a high temperature side is formed of a material having a smaller coefficient of linear expansion than a second member 12 disposed on a low temperature side, and after a core 13 is encased between the first member 11 and the second member 12, the interior is made in a vacuum state. A large difference is not caused between an amount of heat deformation of the first member 11 and an amount of heat deformation of the second member 12, and a deterioration in heat insulating properties of a heating chamber 20 caused by deforming heat-resistant vacuum insulating materials 1 in a thickness direction to separate from a heat-resistant insulating material 21 is prevented. |
