Abstract: A device and method for culturing and/or treating cells is provided. The device comprises a first cell chamber on a gas-permeable carrier and has at least one supply and/or discharge line as well as a frame. The cell chamber is formed by a first film that is gas-permeable and a second film which is microporous that is arranged or is integral with the first film. The frame of the device is useful for covering the films. Also at least one of the first and second films is elastic so that a final volume of the cell chamber can expand to at least 100 times its starting volume. This allows for flexibility of the cell chamber into which cells are introduced therein, and the chamber is between the first and second film. A third film can also be arranged on the second film of which these films being elastic form a second cell chamber having a variable volume of at least 100 times its starting volume.