PURPOSE: To improve the safety of operation and to reduce the cost of installation by heating the outdoor air side surface of a mold material to harden the hydrous layer on the surface of refractories and curing the refractories exposed by releasing from the mold by heating.

CONSTITUTION: The thermosetting monolithic refractories 12 are molded in the following manner: A combustible material 16 is applied on the packing side surface of the mold material 14 required to be released and water is impregnated therein at the time of setting of the mold. The refractories are packed in the packing space formed of the mold material 14. The outdoor air side surface of the mold material 14 is heated by a kerosene burner 24 to burn the combustible material 16 and to supply the moisture contained therein to the surface of the refractories 12. The heating is continued to cure the hydrous layer on the surface of the refractories 12. The mold material 14 is released. The refractories exposed by the releasing are cured by heating. As a result, the conduction of the safe operation is assured.