The invention relates to a device for degassing and gassing containers (3), comprising at least one chamber in which an open container can be accommodated for a degassing and/or gassing process, wherein a cover element (26) for the accommodated open container (3) is provided in the chamber, wherein, for a degassing and/or gassing process, the cover element (26) can be sealingly placed on a container edge (31) of an accommodated open container (3) or into an interior of an accommodated open container (3) and wherein the cover element (26) has at least one opening (260) for a passage of gas. The invention also relates to a method for degassing and gassing.