A method for an x-ray fluorescence measurement, in which the presence of fluorescing target particles is captured in an object (1) to be examined and target particles that are present are localized in the object (1), comprises the steps of (a) producing an x-ray beam (2) by means of a source device (10), wherein the x-ray beam (2) extends through the object (1) in an x-ray beam direction parallel to a first projection direction, (b) irradiating the object (1) with the x-ray beam (2) at a multiplicity of scan positions in a first projection plane, wherein the scan positions are set by a scanning device (20), by means of which the source device and the object (1) are moved relative to one another, (c) detecting x-ray radiation, emitted from the object (1) in a plurality of spatial directions, at each scan position using a detector array device (30), which is securely connected to the source device (10), wherein the detector array device (30) comprises a multiplicity of spectrally selective detector elements (31), which are arranged to detect the x-ray radiation in the multiplicity of spatial directions, and a plurality of stop lamellas (32), which extend in radial directions relative to the x-ray beam direction, which shield the detector elements (31) from x-ray radiation scattered in the object (1) and which are arranged in such a way that the detector elements (31) are able to detect x-ray radiation from all locations within the volume of the x-ray beam in the object (1), and (d) processing detector signals of the detector elements in order to capture x-ray fluorescence of target particles in the detected x-ray radiation and in order to localize the target particles in the object (1) if the x-ray fluorescence is captured, wherein a subset of significant detector elements (31) is sought after for each of a multiplicity of predetermined scan positions, the detector signals of said detector elements facilitating the capture of the x-ray fluorescence of the target parti
