The invention relates to a method for purging containers (2) with a purge gas prior to filling, using a treatment head (1, 1a) on which the respective container (2) is arranged in a sealed position during purging and via which the purge gas is introduced into the container (2) and the purge gas as well as any gaseous and/or vaporous medium, for example air, displaced by the purge gas is discharged from the container (2). The container (2) is emptied before the purge gas is introduced or is subjected to a vacuum from a vacuum source (19). During introduction of the purge as into the container (2) the latter continues to be connected to the vacuum source (19).