PURPOSE: To obtain products having good quality free from pinholes by ingeniously injecting and packing a molding material of a half-melted metal, such as aluminum, into a prescribed metal mold cavity.

CONSTITUTION: The aluminum or the like in a half-melted state is injected and filled into the metal mold cavity 3 by stepwise changing the forcing speed of a ram 12 of an injecting device 10 in correspondence to the shape of the metal mold cavity 3, the temp. and material of the metal mold, etc. The molding material 11 is thus filled into the metal mold cavity by forming the material flow of the molding material 11 in the half-melted state in the metal mold cavity 3 into laminar flow.