Provided is a method for manufacturing an absorbent body (100) for an absorbent article comprising synthetic fibers (10b). This method for manufacturing an absorbent body (100) includes: a cutting step of cutting a belt-shaped synthetic fiber sheet (10bs) into predetermined lengths in a first direction and a second direction intersecting with the first direction so as to form sheet pieces (10bh) that comprise synthetic fibers (10b)； a delivery step of delivering the formed sheet pieces (10bh) to an accumulation part (41)； and an accumulation step of accumulating, in the accumulation part (41), the sheet pieces (10bh) delivered in the delivery step so as to obtain an accumulated body (100a) which is a constituent member of the absorbent body (100).本發明之吸收體之製造方法係包含合成纖維(10b)之吸收性物品用之吸收體(100)之製造方法。該吸收體之製造方法具備：切斷步驟，其係將帶狀之合成纖維片材(10bs)於第1方向及與該第1方向交叉之第2方向上以特定長度切斷而形成包含合成纖維(10b)之薄片(10bh)；搬送步驟，其係將所形成之薄片(10bh)搬送至集聚部(41)；及集聚步驟，其係將搬送步驟中所搬送之薄片(10bh)集聚於集聚部(41)而獲得吸收體(100)之構成構件即集聚體(100a)。
