PURPOSE: To ease the molding of patterns by wax and enable the easy controlling of the distribution density of the channels of the blade material being cast and their sizes by using the cores of ceramics porous material.

CONSTITUTION: Ceramics porous material having voids of 80W98% is molded to the shape close to that of the turbine blade and is set into a metal mold, into which is then injected wax to integrate these. In this case, the ceramics are protruded to the blade surface only in the portions requiring cooling. A lost wax process is applied to this wax molded mold to manufacture a mold and the blade is produced by being directionally solified by an ordinary method. Since this ceramics material elutes in an NaOH molten bath of high temperature, the provision of the continuous fine pores communicating with the surface from the blade inside becomes possible and it becomes possible to forcefully cool the blade.