PURPOSE: To obtain a sound casting without any blow hole by providing a mold at upper part of a holding furnace, reducing the pressure in a mold lower than the pressure in the holding furnace while keeping the reduced pressure in the furnace charging the molten metal, sucking, filling up and solidifying the molten metal in the mold.

CONSTITUTION: The molten metal 4 is charged into a graphite crucible 5 and contained in the holding furnace 1. The pressure in the holding furnace 1 is reduced to the pressure P2 while heating with a heater 2. By this reduced pressure, gas of hydrogen, etc., and non-metallic inclusion in the molten metal 4 are emitted. The pressure in cavity 8 in the metallic mold 9 is reduced. The pressure P1 in the cavity 8 is reduced so as to come to lower than the pressure P2 in the holding furnace 1. By this pressure difference, the molten metal 4 is slowly sucked and filled up in the cavity 8 through a pouring tube 11. At the time when the filling-up completes, the inner part in the holding furnace 1 is pressurized to intensely push the molten metal 4 and running of the molten metal in the cavity 8 is made to good. Enclosing of the gas can be surely prevented and the sound casting without any defect, is obtd.