PURPOSE: To make it possible to strongly and correctly join a resin mold to a metal frame by a simple method and at the same time to facilitate the exchange of the resin mold by a method wherein split metal frames, on the top surfaces of which a large number of vertical holes are bored and from the inner side surfaces of which horizontal holes communicating to each vertical hole are respectively bored, are employed.

CONSTITUTION: Vertical holes 31, 32... are bored with a drill or the like from the top surfaces 2 of split frames 11 and 12 made of aluminum, iron or the like. Horizontal holes 311W313 and 321W323 are bored from the inner side surfaces 4 of the frames so as to communicate with the respective vertical hole 31 and 32. A master form 5 is set in the interior of the frames 11 and 12. Liquid resin 9 is poured between gaps made between the frames and the master form. The resin is cured and the frames 11 and 12 are split off so as to remove the master form 5. Resin molds 91 and 92 prevail through the horizontal holes 311W313 and 321W323 bored in the inner side surfaces 4 of the frames 11 and 12 to the vertical holes 31 and 32 so as to be integrally cured in order to produce strong anchoring effect, resulting in strongly form the frames 11 and 12 and the resin molds 91 and 92 to each other.