The tubular radiation absorbing device (1) for solar thermal applications has a central tube (2) and a glass tubular jacket (3) surrounding the central tube (2) so that a ring-shaped space (4) is formed between the central tube (2) and the tubular jacket (3). The ring-shaped space (4) contains at least one inert gas with a partial pressure of 3 to 200 mbar. Alternatively in another embodiment a gas-tight closed container (10) filled with at least one inert gas is arranged in the ring-shaped space (4). The container (10) has a device for supplying inert gas to the ring-shaped space (4) in order to compensate for increased heat losses due to diffusion of hydrogen into the ring-shaped space (4) from the heat carrier medium.