PURPOSE: To prevent a material from expanding and a dimensional error from being generated by pressing a press die to the material mounted on a pedestal as it is inserted between right and left material pressing plates.

CONSTITUTION: The material A is mounted on the pedestal 5 and a movable frame 3 is lowered by a elevating/lowering cylinder device 2. When the material pressing plate 11 is positioned at the same height as the shape A, the material pressing plate 11 is pushed out by a press plate supporting mean 12 toward the material A and the material A is inserted between the right and left material pressing plates 11. Under this state, a movable frame 3 is lowered further, the press die 4 mounted on the movable frame 3 is pressed to the material A and the material is pressed as the expansion of the shape A is prevented by the material pressing plate 11. At this time, as the material pressing plate 11 is supported by the pedestal 5, the movable frame 3 is lowered.