The present invention relates to a method for producing a disposable diaper of the open type having a main part (4), comprising a front region (6) having front lateral longitudinal edges (42), a rear region (8) having rear lateral longitudinal edges (41), and a crotch region (10) located between the same in the longitudinal direction (28) and disposed between the legs of a user, wherein the main part (4) comprises a suction body (12), and having rear side sections (20) attached to the rear region (8) on both sides, and front side sections (22) attached to the front region (6) on both sides and extending in the lateral direction (30) beyond the lateral front and rear longitudinal edges (42, 41) of the main part (4) and connecting the front region (6) and the rear region (8) to each other in the worn state of the disposable incontinence diaper. In order to form leg cutout regions, the side sections (20, 22) are configured such that they extend obliquely to the longitudinal direction (28) or are curved, at least at the edges (17) facing the crotch region (10), and the main part (4) is configured in the shape of an hour glass, at least in the crotch region, comprising the following steps: - feeding an endless flat material web (50, 50a) in a longitudinal direction (28) for the production of material sections (66, 66a) for forming the side sections (20, 22), - forming first material recesses (52) along a first cutting line (100) at a side edge (70, 70a, 70b) of the flat material web (50, 50a) for creating contoured cutouts in the flat material web (50, 50a), wherein an imaginary parallel PL to the longitudinal direction, which is placed against the point P of the maximum extension of the cutout transversely to the longitudinal direction (28), defines an outer partial region (80) and an inner partial region (81) of the flat material web (50), - folding of the flat material web (50, 50a) about at least one first folding line (36) extending in the longitudinal direction (28
