To provide a method and an apparatus for a pressure casting, in which molten metal is poured into a cavity by the pressure of the steam generated from a sealing material containing moisture by the heat of a casting mold while mounting a steam pressure lid having the sealing material containing moisture fixed to the inside thereof on the casting mold in the sealed state, and by which a stable product can be cast without requiring the adjustment of the moisture content in the sealing material very much.

The molten metal in the casting mold 20 is pushed into the cavity by the pressure of the compressed air supplied into the steam pressure lid 1 from an air tank 10 and the pressure of the steam from the moisture contained in the sealing material 8. Since the pressure can be controlled so as to be constant by mainly utilizing the pressure of the compressed air, and the adjustment of the moisture to be contained in the sealing material 8 is not required so much, an inexpensive asbestos substitute like paper can be used.