The invention relates to an airbag (12) of a vehicle occupant restraint system (10) comprising plural juxtaposed compartments (16) delimited outwardly by opposing external walls (18) and against each other by partitions (20), wherein the airbag (12), in the inflated condition, has a form overall bent and elongate in cross-section. In the bending area the external wall (18) includes a cut-out (22) that is closed by an inserted insert (24) tensioned in the deployed condition which in the longitudinal direction has a length (LE) different in the bending area from the opposing external wall portion (28) of the chamber (16) so as to produce the bending.The invention furthermore relates to a method of manufacturing an airbag of this type.