Abstract: To fold-in an end of a folded waistband (7) into the inside thereof, e.g. for a trouser or skirt, the upper (7a) and lower (7b) parts of the U-shaped waistband are seized by upper and lower gripping elements (5,9,18;6,10,19) such as paired fingers, or tongs, which are arranged in an upper and lower mechanical module (1,2). The ends of the folded upper (7a) and lower (7b) parts of the waistband are then opened, by spreading-apart of the gripping elements by relative movement of the modules 1,2, and the protruding terminal end portions of the waistband are folded into the inside of the waistband by sliders (12,13).