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).
