PURPOSE: To make the demolition work of lining extremely easy by a method wherein intermediate members having a considerably low strength in comparison with castable lining material are laid between a steel plate of a stack and the castable lining material, and a pick is stuck into the intermediate members to demolish the lining.

CONSTITUTION: For example, foamed polystyrene members 10 and 11 are fixed by adhesive to lay them between a steel plate 1 and a castable lining material 2. Those foamed polystyrene members 10 and 11 are made of the same material but the foamed polystyrene member 10 is arranged longitudinally and the member 11 laterally. The intermediate member is not limited to foamed polystyren but also such foamed plastics as polyurethane foam, or inorganic mold products like rock wool or glass wool is applicable. In demolition work, when a pick 7 is stuck into the polystyrene foam members 10 and 11 from above or the side and tilted down toward the inside of a stack, the lining 2 is collapsed and falls down into the stack. As the pick 7 is stuck into the intermediate members having a low strength to break the lining, demolition work is easily done and the efficiency can be remarkably improved.