The application relates to an absorbent disposable incontinence diaper (2, 2a) of the open type having an at least three-part diaper cover (3) with an inner side (30) and an outer side (31), the diaper cover comprising a main part (4) and at least two separate rear side parts (16). The main part (4) has a front region (6), a rear region (8) and a crotch region (12), which lies therebetween in the longitudinal direction (21) and comes to lie between the legs of a user. The rear side parts (16) are arranged on both sides of the rear region (8) of the main part (4) in such a manner that said rear side parts (16) are fixed in first overlap regions (40) with the outer side thereof on the inner side of the main part (4) along rear, lateral longitudinal edges (20). The rear side parts (16) extend in the transverse direction (22) over the rear lateral longitudinal edges (20) of the main part (4) and have closure means (10). The main part (4) and the rear side parts (16) comprise a nonwoven material or are made therefrom. The diaper cover (3) extends continuously over a length L1 from a front end (33) of the diaper cover (3) via the crotch region (12) to a rear end (34) of the diaper cover (3). An absorption insert (5) having an inner side and an outer side is arranged on the inner side (30) of the diaper cover (3), the absorption insert (5) comprising a liquid-impermeable back sheet (62) and a top sheet (64), between which an absorption body (7) is arranged. The absorption insert (5) extends into the first overlap regions (40) and is fixed there at least in some sections with the outer side thereof on the diaper cover (3). The absorption insert (5) has a length L2, where L2
