Europium abundances for 112 FGK stars of the galactic thick and thin disks with metallicity –1.0 < [Fe/H] < +0.3 are determined. The spectra of the stars under investigation were obtained with the 1.93-m telescope of the Haute-Provence Observatory (France) equipped with echelle-spectrometer ELODIE. The results are based on an analysis of spectra with typical S/N values from 100 to 300 and with a resolution of 42 000. These estimates are obtained from synthetic spectra using the LTE model atmosphere with a sophisticated consideration of hyperfine structure. Our analysis of the relationship between europium abundances and metallicity for the selected stars of the thick and thin disks of the Galaxy shows that the values of europium abundances in the disks are different. The results of our comparison between the europium abundances and magnesium abundances point to a similar origin of these elements for [Fe/H] < –0.2 dex and to probably distinct origin of them for [Fe/H] > –0.2 dex.