PURPOSE: To provide inexpensive highly reliable heat insulating structure adaptable even to a large-scaled adsorbing device or catalyst cylinder, reduced in heat capacity and preventing the leak in a heat insulating material of a pressure-resistant container used in a temp. change type adsorbing and separating method repeating the adsorption and regeneration due to a temp. change or an adsorbing device or catalyst cylinder becoming an issue in the temp. drop of a filler generated by the heat capacity of the pressure-resistant container.

CONSTITUTION: A heat insulating structure is constituted by providing ring- shaped heat insulating material support plates crossing the flow direction of a fluid at an almost right angle along the inner peripheral surface of a pressure- resistant container over two or more stages and providing a heat insulating material 5 between the heat insulating material support plates 4 to line the inner peripheral surface of the container.