PURPOSE: To obtain excellent artificial marble free from cracks and buckling whitening during molding, by spraying a gel coat resin through a plastic film to the surface of molded article, after curing, further casting a resin composition, curing and demolding.

CONSTITUTION: A plastic film is stuck in vacuum to the surface of a mold having a shape corresponding to the form of a molded article. Then, a gel coat resin is sprayed on the plastic film. After curing of the gel coat resin, further a resin composition is cast into the mold, cured and demolded to give the objective molded article. By the production of the molded article, the flexible plastic film is laid between the surface of the mold and the coating film of gel coat, force caused by adhesion between the surface of existing mold and the coating film of gel coat is eliminated and since any resisting force against powder caused by curing shrinkage of resin composition cast will not occur, the same effects as effects prepared by demolding molded articles in the midst of curing of cast resin by conventional method can be obtained.