A continuous web processing device including a folding unit that extends in a conveyance direction. The folding unit has a central guide that comes into contact with the bottom of the crotch part of an absorbent article being processed, a pair of side guides that come into contact with the front waistline portion and the rear waistline portion of the absorbent article, and a superimposing roller that superimposes the front waistline portion and the rear waistline portion one on the other. A spacing between the pair of side guides becomes narrower in the downstream conveyance direction. Ends of the side guides are located further upstream than an end of the central guide. The superimposing roller superimposes the front waistline portion and the rear waistline portion of the absorbent article one on the other downstream from the side guides.