The invention relates to a retaining device (30) for absorber tubes (10) which have a metal tube (12) and a glass cladding tube (16). The retaining device (30) comprises a tube clamp (40) made of two tube clamp halves (42a, b) which have a main part (43) with retaining means (44). The tube clamp (40) surrounds the metal tube (12) in the mounted state, and the retaining means (44) rest against the exterior of the metal tube (12). A thermal radiation shield (60) is arranged on the interior of the main part (43) of the tube clamp (40) in order to reduce the loss of heat at the ends of the metal tubes of the absorber tube (10).