Known devices for heat treatment comprise a process space surrounded by a furnace lining made of quartz glass, a heating facility, and a reflector. In order to provide, on this basis, a device for heat treatment having a furnace lining that can be manufactured easily and in variable shapes and enables rapid heating and cooling of the material to be heated and short process times and is characterized by its long service life, the invention proposes that the furnace lining comprises multiple wall elements having a side facing the process space and a side facing away from the process space, and that at least one of the wall elements comprises multiple quartz glass tubes that are connected to each other by means of an SiO2-containing connecting mass.
