In a spectroscopic process a sample for producing a test spectral line or spectrum of at least one component contained in the sample is stimulated and the transmitted and/or emitted electromagnetic rays are used to create the test spectral line or spectrum. In order to improve such a spectroscopic process to such an extent that variations of certain parameters, which alter the shape and/or occurrence of a spectral line, are compensated, a comparison spectral line or spectrum of a known comparison material is produced under substantially the same parameters as the sample. The comparison spectral line or spectrum is compared with an ideal comparison spectral line or spectrum in order to calculate a transfer function, andthe transfer function is applied to the test spectral line or spectrum in order to calculate a corrected test spectral line or spectrum.