To obtain high quality cast products by securing the supplying quantity of metallic material in a high accuracy and coping with the change of the supply.

A molten metallic material 51 held in a molten metal furnace 49 is transported from a molten metal supplying tube 47 into a material holding chamber 45 in front of a piston 33 through a material discharging passage 75 of a switch valve 71 by driving a pump 53. The switch valve 71 can be shifted in the orthogonal direction to the paper surface in the picture, and the metallic material 51 in the material holding chamber 45 is supplied into an injection sleeve 25 by advancedly shifting the piston 33 in a state the material holding chamber 45 is communicated with the injection sleeve 25 with this shifting.