PURPOSE: To obtain a formed product having excellent pressure resistance and casting surface, etc., by forming a reversed trapezoidal recessed cutting part on the inner peripheral upper surface of an ejection sleeve, fitting a fitting member arranged with a gas venting hole communicated with a vacuum pump and evacuating the inside of the ejection sleeve.

CONSTITUTION: Molten metal is poured into the ejection sleeve 7, and the advancing speed of a plunger tip 9 is changed from a low speed to high speed at the point of time when the tip kicks a limit switch 42 by advancing a plunger tip 9 at low speed. The air in the ejection sleeve 7 is sucked to the reduced pressure state with the vacuum pump 16 in the condition of closing a molten metal pouring hole 10 with the plunger tip 9. In the case the molten metal is comparatively slowly solidified, the limit switch 42 is set so as to execute the change-over of the speed at the position near a gate 14, and the fitting member, in which an air venting hole is set near the gate 14, is used. In the case the molten metal is comparatively quickly solidified, on the contrary, the fitting member, in which the air venting hole is set distant from the gate 14, is used. In such a way, the formed product having excellent pressure resistance and casting surface, etc., is obtd., by sufficiently evacuating the ejection sleeve 7.