A sailor roller (120) comprises a pair of pressing rollers (121, 122) which presses a web (200) and a center roller (123) which is disposed between the pressing rollers (121, 122) and presses the center region (203) of the web (200). The positions of the web (200) which are pressed by the pressing rollers (121, 122) are to be the start points of folding. The pressing rollers (121, 122) are tapered in such a manner that the diameter thereof decreases toward the outer sides in the crossing direction (CD). That is, the pressing rollers (121, 122) have tapered surfaces (121a, 122a) tapering toward the side edges of the web (200).
