To provide a thin-walled and/or a thick-walled casting having the weldability and/or high developability without developing contained gas and/or void, and an L-shaped air-tight casting, with respect to a non-ferrous alloy casting with a vacuum die casting.

This vacuum die casting method contains a process for holding the non-ferrous alloy material in the molten-state into a holding furnace (11), a process for transporting the material having a setting quantity from the holding furnace to the die (18) in an injector and a process for cooling by compressing the material in the die. In each process, in the area which is not occupied by a holding means, the material is always protected from the contact with the air in the gas atmosphere whose relative density is larger than that of the air, causing to always eliminate the fear of contamination and oxidation.