PURPOSE: To fold a cutform on a correct folding position by providing a folding member, folded along the outer peripheral surface of a rotating drum, and a folding roller discharging a cutform in a folded condition from the rotating drum to fold the cutform.

CONSTITUTION: This folding device is provided with a rotating drum 10, having retaining mechanisms 20a-20d, which are insertedly retaining one end side of a cutform 1 with a given folded position of the cutform 1 as a boundary and are intermittently rotated at every given angle; and pressedly contacting rollers 28a-28d as folding members, which are provided on the periphery of this rotating drum 10 and are contacted with the other end part of the cutform 1 when the rotating drum 10 is rotated, to fold the cutform 1 along the outer periphery of the rotating drum 10. The cutform 1 formed into a folded condition is discharged from the rotating dram 10, and is folded with folding rollers 31 and 32.