A new research project on spectral analysis which aims to characterize the vertical stratification of element abundances in stellar atmospheres of chemically peculiar (CP) stars, is discussed in detail. Some results on detection of vertical abundance stratification in several slowly rotating main sequence CP stars are presented and considered as an indicator of the effectiveness of the atomic diffusion mechanism responsible for the observed peculiarities of chemical abundances. This study is carried out in the frame of Project VeSElkA (Vertical Stratification of Elements Abundance) for which 34 slowly rotating CP stars have been observed with the ESPaDOnS spectropolarimetre at CFHT.
