Patent ID: 7281566

Claim:
A method for manufacturing a mold having a porous layer having a three-dimensional porous structure on a surface of a cavity of a shell, the method comprising, a step D for scattering and adhering combustible powdery particles around a wax mold, which is a lost pattern, to thereby form a layer of combustible powdery particles around thereof, a step E for coating a film of a ceramic precursor slurry around the wax mold having the layer of the powdery particles formed thereon, a step F for subjecting the wax mold coated with the slurry film to a heat treatment at 100 to 180° C., to thereby dewax only the wax mold without said combustible powdery particles burning and vanishing, and a step G for firing the slurry film, to thereby burn and vanish the powdery particles in the slurry film and form a shell.