A method for the spectroscopic analysis of a sample is provided. The method including the illumination of the sample to be analyzed by a plurality of luminous excitation rays with respective wavelengths; the acquisition and the pre-treatment of frontal fluorescence spectra, each spectrum corresponding to a respective luminous excitation ray; for each sample, the calculation of a score vector by applying a multi-channel statistical model to the pre-treated spectra; and the determination of at least one parameter selected from a quality indicator of the sample and a parameter characterizing a method that has been applied to the sample, from said score vector. The average spectral distance between the luminous excitation rays is at least 50 nm, over a spectral range of at least 100 nm. The invention also relates to an appliance for implementing such a method.