A device for identifying materials on a conveyor belt by means of X-ray fluorescence comprises an X-ray source, from which X-ray radiation is guided onto material parts, a detector head containing an X-ray detector with a multiplicity of detector elements arranged in a planar fashion for receiving X-ray radiation and converting it into electrical charge signals, and an electronic unit for reading out and processing the charge signals, which comprises for each individual detector element a signal channel having a discriminator unit with a plurality of energy thresholds and a counting unit apparatus for converting the signals into digital counting events, wherein the electronic units are interconnected such that simultaneous occurrence of signals on more than one detector element can be identified and treated separately.