PURPOSE: To easily take out a work without lowering the strength of a lower mold die by a method wherein the part incorporated into the lower mold die of a liner is formed narrower than a part protruding from the lower mold die.

CONSTITUTION: Liners 25 incorporated into individual outside parts 24a in recessed parts 24 at the outer circumferential part of a lower mold die 23 are incorporated into the lower mold die 23 in such a way that they are formed rectangular whose base parts 25b are narrower than their tip parts 25a, and the tip parts 25a protrude to the outside of the lower mold die 23. Thereby, when a work 43 is taken out, the liners 25 are pulled into the inside, the work 43 is taken out smoothly, and a receiver-face width required to press and mold a rib part can be ensured at the work 43 which is cylindrical. In addition, since the width of parts between the recessed parts 24 into which the liners 25 for the lower mold die 23 can be ensured to be wide, the strength of the lower mold die 23 can be ensured to be high even when the liners 25 are many.