Abstract: The invention relates to a device (3) for absorbing electromagnetic radiation, in particular solar radiation. The device (3) has at least one 11cxible film pocket (4) that is divided into chambers (15). Said chambers (15) are connected to at least one feed clement (5) and at least one discharge element (6), by means of which a heat transfer medium can be fed to and discharged from the chambers (15). To prevent a build-up of pressure in the heat transfer medium caused by gravity and thus unwanted stress on the film material, at least one pressure reducing clement (21) is provided between at least two of the chambers (15) or fllm pockets (4). Said pressure reducing clement (21) limits the pressure of the heat transfer medium.