A method (1) includes: a step (S10) of conveying the wearing article (1) in such a manner that a front waistline portion (10) and a back waistline portion (20) extend in a conveyance direction (MD) of the wearing article (1) a step (S20) of changing the conveyance direction (MD) of the wearing article (1) by 90 degrees a step (S30) of folding a flap portion (70) toward the front waistline portion (10), while conveying the wearing article (1) a step (S40) of folding the wearing article (1) along a middle portion, which is located in the middle between the front waistline portion (10) and a crotch portion (30) in the front-to-back direction of the wearing article (1), in such a manner that the front waistline portion (10) and the crotch portion (30) face each other.
