PURPOSE: To provide excellent heat insulation, releasability and compressive strength by filling the heat insulation material consisting of the powder of lower heat conductivity than that of a die material and the binder in a recess on the lattice carved surface of the die made of porous metallic material.

CONSTITUTION: The INVAR alloy powder consisting of, by mass, 36% Ni and 60% Fe is compacted by an appropriate method, sintered to make a lattice die of sintered alloy of porosity of 40-60%. The heat insulation material 3 where diatomaceous earth or cork of lower heat conductivity than that of sintered alloy of the die is mixed with water glass is filled in a recess 2 on a lattice carved surface 1 of the die. Diatomaceous earth which is not carbonated while in use is preferably used for the heat insulation material 3, and its composition is preferably, 100 pts.wt. diatomaceous earth, 10 pts.wt. water glass, and 500 pts.wt. water, and these elements are mixed and kneaded, and the mixture is preferably coated on the carved surface by a spatula-shaped jig, etc. The yield can be remarkably improved when the lattice body is cast at the die temperature of 225°C.