Abstract: The application describes an apparatus and a method for the thermal treatment of substrates, in particular thin film substrates for photovoltaic applications. The apparatus comprises at least one substrate carrier for supporting a substrate, a heating unit having at least one heating element for heating a substrate located on the substrate carrier and at least one heating element carrier for supporting the at least one heating element. The heating element carrier is designed to allow a local change in distance between the substrate carrier and the heating element, so as to be able to provide locally different heating intensities. In the method such a change in distance is carried out during the thermal treatment.