|A method for the determination of nanofibrous mats chemical composition based on Raman spectroscopy and singular value decomposition is presented. The electrospinning method, that uses electrostatic forces to produce nanofibers from a solution, was used to prepare samples consisting of various polymers in a single nanofibrous layer. Characterization of produced materials could be of great help in the optimization of the electrospinning process or in the quality control process of bought materials prior to their application. The characterization method depends on the intended end use of the material. Confocal Raman microscopy has become a promising contactless and non-destructive method suitable for the characterization and structural studies of polymeric nanofibrous materials. Since Raman spectra provide information about chemical composition from molecular vibrations characteristic of each compound, micro-Raman can easily discern materials otherwise hardly discernible due to similar optical properties (e.g. colour, refractive index). Exploiting chemical contrast, Raman can be used for chemical mapping and imaging down to the micrometre scale. Moreover, local chemical composition (e.g. ratio between polymers) could be expressed as the relative fraction of the particular chemical compound. Using Raman mapping and a statistical evaluation method, we were able to determine chemical composition of various local areas within each sample and to distinguish substantial changes in the distribution of polymers. The results, in the form of individual local Raman spectra, were presented in the form of graphs showing relative fractions and Raman maps depicting variations in chemical composition of selected microregions. The present work demonstrates on several examples the applicability of confocal Raman microscopy in the determination of variations in the chemical composition of different polymeric nanofibrous layers. Based on the obtained results, the method of electrospinning is optimized in order to achieve a better homogeneity of the distribution of a mixture of polymers in the nanofibrous layer.