A device for identifying materials, in particular metal parts such as scrap particles, on a conveyor belt by means of X-ray fluorescence comprising an X-ray source, from which X-ray radiation is guided onto the material parts to be examined on the conveyor belt, comprising a detector head containing an X-ray detector array, characterized in that the device comprises an X-ray detector array having a multiplicity of detector elements (113, 114, 115) arranged in a planar fashion for receiving X-ray radiation scattered at the material parts or excited by the latter and for converting said X-ray radiation into electrical charge signals, and also an electronic unit for reading out and processing the charge signals from the detector elements (113, 114, 115), which comprises for each individual detector element (113, 114, 115) of the X-ray detector array a signal channel having in each case: - a discriminator unit having at least two adjustable discriminator thresholds (116, 122) for detecting all Gaussian curve-like signals whose amplitude is greater than one of the two or simultaneously greater than both discriminator thresholds (116, 122), - and also one counting unit (118, 121) per discriminator threshold (116, 122) for converting the analog Gaussian curve-like signals into digital counting events, that the individual detector elements (113, 114, 115) of the X-ray detector array have a spatial resolution of 50 μm to 500 μm with a sensitivity to X-ray radiation in an energy range of between 500 eV and 30 keV, with an energy resolution of less than 0.5 keV at counting rates of up to 100 kcps and with respect to an energy of 8.04 keV, that the electronic unit comprises a signal channel for each individual detector element (113, 114, 115) of the X-ray detector array, that each discriminator unit for a specific detector element is in each case electrically connected to the discriminator units of the detector elements (113, 115) that are spatially directly adjacent to said detector element, wherein all the discriminator units are interconnected with one another via a digital and/or analog circuit (140, 142, 144, 146) in such a way that simultaneous occurrence of signals on more than one detector element (113, 114, 115) can be identified and treated electrically separately, that the discriminator thresholds of each individual detector element group (603, 604, 605, 606, 607) can be set independently of one another, and that as a result each group can be allocated one or a plurality of individual energy windows for the detection of the impinging X-ray radiation, and that individual groups of detector elements in the TDI (= "Time Delay Integration") mode are operated synchronously with the instantaneous speed of the conveyor belt. - a discriminator unit having at least two adjustable discriminator thresholds (116, 122) for detecting all Gaussian curve-like signals whose amplitude is greater than one of the two or simultaneously greater than both discriminator thresholds (116, 122), - and also one counting unit (118, 121) per discriminator threshold (116, 122) for converting the analog Gaussian curve-like signals into digital counting events, that the electronic unit comprises a signal channel for each individual detector element (113, 114, 115) of the X-ray detector array, that each discriminator unit for a specific detector element is in each case electrically connected to the discriminator units of the detector elements (113, 115) that are spatially directly adjacent to said detector element, wherein all the discriminator units are interconnected with one another via a digital and/or analog circuit (140, 142, 144, 146) in such a way that simultaneous occurrence of signals on more than one detector element (113, 114, 115) can be identified and treated electrically separately, that the discriminator thresholds of each individual detector element group (603, 604, 605, 606, 607) can be set independently of one another, and that as a result each group can be allocated one or a plurality of individual energy windows for the detection of the impinging X-ray radiation, and that individual groups of detector elements in the TDI (= "Time Delay Integration") mode are operated synchronously with the instantaneous speed of the conveyor belt.