PURPOSE: To provide a web folding device having the capability of hardly generating a web fracture, and performing a high speed and soft web folding work.

CONSTITUTION: This device is constituted of a folding roller 1 cantilevered in such a way as freely rotatable, and a presser plate 2 laid at the outlet and free end side of the roller 1. A web W is made to move in contact with the roller 1 for travel along an S-curve in a travel direction. In addition, the edge of the free end of the roller 1 is positioned on the predetermined folding line L extending in the lengthwise direction of the web W. Furthermore, the web W1 of a section coming out without contacting the roller 1 is folded on the web WO of a section coming out after contact with the roller 1, using the presser plate 2. The web W is thereby folded in two.