Apparatus and method for thermal treatment of substrates

The invention relates to a device and a method for thermally treating substrates, in which the substrate is heated by a heating plate. The aim of the invention is to improve the thermal homogeneity. To this end, the heating plate is heated using a number of heating elements that can be separately controlled, the temperature of the heating elements is measured and the heating process is controlled by a PID controller. In addition, the temperature of the substrate surface facing away from the heating plate is locally measured, the temperature distribution over the substrate surface is determined according to the measured temperatures and set values for the temperature of the individual heating elements are determined and transmitted to the PID controller.