A method is provided for correcting at least one portion of a spectrum, in particular a Raman spectrum, by eliminating a baseline which is due to a perturbing spectrum, in particular due to a fluorescence spectrum, superimposed on the spectrum, wherein i) a convex envelope of the spectrum is determined, at least in the portion of the spectrum which is to be corrected, and ii) the convex part of the envelope lying below the spectrum is subtracted from the spectrum in the portion to be corrected. Before step i), iii) a convex function f is added to the spectrum in the portion to be corrected.