PURPOSE: To obtain a cast product having stable chilled layer by binding many slender bar materials into a bundle to form a metallic mold and forming a mold surface with the end parts of the metallic mold members.

CONSTITUTION: A master mold 20 is set on a molding board and a cylindrical holding frame 11 having square cross section is laid so as to surrounded the master mold 20. The metallic mold members 12 are charged little by little from the upper surface opening part of the holding frame 11 and filled up. The lower side end parts of the metallic mold members 12 are abutted on the master mold and moved upward by this portion and the projecting part 21 having shape similar to the master mold 20 is formed by the upper side end parts of the metallic mold members 12 to form the reverse shaped cavity 22. Bolts 14 are fastened through a pressing member 15 to fix the metallic mold members 12. Backup members 13 are filled into the reverse shaped cavity 22 and solidified. The metallic mold 10 is turned over and the master mold 20 is taken out to form the cavity 16 for product. Since the heat conductivity among adjacent metallic mold members is low, the molten metal charged at the initial stage forms the sufficiently cooled chilled layer.