To provide a casting method capable of cost effectively producing a high-quality casting with extremely reduced inclusion defects of gas and oxide film in an energy-saving manner.

A seal plate 7 is arranged between a mold cavity 2 and a stoke 6 to seal a sprue 3 and to decompress the mold cavity 2. Next, the inside of the stoke is decompressed through a decompression groove 10 disposed on a lower face of the seal plate 7 to suck molten metal and at the point of the time the molten metal advances into the decompression groove, the seal plate is driven to move the opening 8 between the sprue 7 and the stoke and the mold cavity is filled with the molten metal by the differential pressure from the mold cavity. The use of a consumable seal is also possible as the seal of the sprue. In this case, the seal lower part is formed as the opening. The mold cavity is filled with the molten metal. When the mold cavity is filled with the molten metal, the seal plate is immediately moved to close the sprue and an external air pressure is acted through an outdoor air vent hole 11 on the molten metal in the stoke to allow the molten metal to drop into a holding furnace 4. Further, the unsolidified molten metal in the mold cavity is pressurized at need.