A method for identifying a material contained in a sample. The sample is subjected to irradiation via ionizing electromagnetic radiation, for example X-rays. The sample is inserted between a source emitting the radiation and a spectrometric detector configured to acquire a spectrum of the radiation transmitted by the sample. The spectrum is subject to different treatment operations to enable classification of the material. The steps are, consecutively: reducing dimensionality, followed by projecting along the predefined projection vectors. Projection makes it possible to establish classification parameters, on the basis of which classification is established.