To provide a folding drum for a web fold-up device and provide such a web fold-up device capable of preventing a folded leaf from end folding in the downstream in the drum rotating direction.

The folding drum 8 of the web fold-up device has a folding blade 83 on its peripheral surface, and a web tight attachment preventing means 84 to prevent a web 20 wound on the periphery from tightly attaching to the peripheral surface is installed downstream in the drum rotating direction of the folding blade 83.