A method for analyzing a sample by diffractometry and a diffractometer, where the diffractometer includes a collimated source, a detection collimator, and a spectrometric detector, the detection axis of the detector and the collimator form a diffraction angle with the central axis of an incident beam and an energy spectrum is established for each pixel of the detector. The measured spectra are readjusted by a change in variable that takes into account the energy of the scattered radiation and the angle of observation. The measured are combined and a check is made on the implementation of at least one multi-material criterion representative of the presence of a plurality of layers of materials and groups of pixels are formed according to the results of this check, where each group corresponds to a single layer of material and the measured spectra obtained for the pixels of the group are combined.