PURPOSE: To enable application of electric discharge machining to die machining and to improve wear resistance compared with the conventional metallic die by using electric conductive ceramic having silicon nitride and titanium nitride as main components as die material.

CONSTITUTION: TiN as electric conductive component is blended to SIALON component adding Y2O3, AlN, Al2O3 to Si3N4. This is formed and burnt to produce a block 1, and this is wire-cut by wire electric discharge machining to adjust the prescribed size, and then divided into two blocks by the wire-cut. A cavity 2 is machined in the partition face of one side block 1, by die milling electric discharge machining using a graphite electrode, and a runner 3 is machined in the other side block 1 to make die. This die is set to a die casting machine and aluminum alloy is poured and shotted. In this way, the wear and crack are not quite recognized and the burning of molten alloy is prevented.