The results of the comparison of TEY and transmission methods of X-ray absorption spectra measurements as well as "thickness effect" modeling in the linear absorption coefficient spectral dependences of the C ₆₀ -films in the NEXAFS C1s-spectra are represented. The calculations were performed with using linear absorption coefficient spectra obtained in TEY mode as the true (undistorted) data. The modelling results are in good agreement with the experiment. All NEXAFS C1s-spectra was carried out at the BESSY II using synchrotron radiation from the Russian-German dipole beamline.