PURPOSE: To easily and efficiently manufacture a casting cylinder with high quality by advancing a core supported with the one end thereof as cantilever state to the position near the thick forming part at the time of unsolidified state of molten metal in a metallic mold and further advancing applying the large pressure.

CONSTITUTION: In a cavity 41 in the metallic mold M, the core 36 supported with the one end thereof is positioned as the cantilever state. This core 36 is composed of a heat resistant steel and has a straight line part 36a and tapered part 36b fit to through hole part 44a in a bush 44. Successively, the molten metal is filled up in the cavity 41 through a sprue 42. When the molten metal in the metallic mold M is unsolidified state, the core 36 is advanced to the position near the thick forming part in a product so as to fill up the molten metal into the cavity 41 without any idle space. When the solidification of a gate 42a is completed and the solidification at the part in contact with the metallic mold M starts, the core 36 is advanced to the prescribed position with the large pressure to execute squeezing to the molten metal.