The invention comprises a method and a device for changing removable carrier units (8a′, 8b′) with flat packaging material (10) wound on supply rolls (9), in particular, packaging film (11) within a packaging machine (3), which is equipped with devices for at least partially wrapping piece goods, containers, article groups, etc., with flat packaging material (10). With the method removable carrier units (8a, 8b) with new supply rolls (9) are fed in a series one after the other to a work area (AB) of a handling device (5), the work area (AB) of which extends into at least one position of the operating position of the removable carrier unit (8a′, 8b′) arranged in the packaging machine (3), which is equipped with a supply roll (9), so that it replaces removable carrier units (8a′, 8b′) located in the packaging machine (3) and used up supply rolls (9′) with new removable carrier units (8a, 8b) with in each case a new supply roll (9). Here respective removable carrier units (8a, 8b) are inserted alternately in at least two different installation positions of the packaging machine (3) and its flat packaging material (10) is connected with the packaging material still located in the packaging machine (3).