NOVELTY - Gas container comprises a container lower part including a trough (21) for accommodating the biomass (30), and an upper container-covering (25) formed by a membrane arrangement comprising an outer membrane (26) and an inner membrane (27), whose lower position is restricted under the influence of a supporting structure against gravity, where the introduced biomass is maintained at a distance with respect to the supporting structure. The supporting structure has a floating body arrangement comprising floating bodies and is mounted depending on the level of the biomass present in the trough.    USE - The gas container is useful for accommodating biogas of a biogas plant.    ADVANTAGE - The gas container ensures safe operation, and makes use of the data that is recovered separately or calculated for individual gas container of a biogas plant, when the gas containers are out of service, or when the control system of the gas container is under non-operative conditions.    DETAILED DESCRIPTION - Gas container for accommodating biogas of a biogas plant, comprises a container lower part including a trough (21) for accommodating the biomass (30), and an upper container-covering (25) formed by a membrane arrangement comprising an outer membrane (26) and at least one inner membrane (27), whose lower position is restricted under the influence of a supporting structure against gravity, where the introduced biomass is maintained at a distance with respect to the supporting structure. The supporting structure has a floating body arrangement with at least one floating body and is mounted depending on the level of the biomass present in the trough by its variable height.    DESCRIPTION OF DRAWING(S) - The drawing shows a lateral schematic representation of the gas container with a maximum level of a filled biomass, with a plant control system and a measuring device as blocks, and a schematic representation of the gas container with a lower level of the filled biomass, respectively.    Trough (21)    Container covering (25)    Outer membrane (26)    Inner membrane (27)    Biomass (30)