A method of manufacturing an absorbent article includes forming a pair of side flap-folded sections by folding a continuous sheet such that end sections in a width direction of the continuous sheet are folded inwardly in the width direction, while the continuous sheet is being transported in a continuous direction of the continuous sheet, producing a flap segment by segmenting the continuous sheet at a predetermined pitch in the continuous direction, joining the flap segment to a continuous body of absorbent main bodies in an overlapped manner, while the continuous body of absorbent main bodies is being transported in a transport direction corresponding to a continuous direction of the continuous body, and dividing the flap segment into a section having the pair of first side flaps and a section having the pair of second side flaps by segmenting the continuous body of absorbent main bodies.
