Experimental evidence concerning an influence of the in situ scraping process on the XPS core-level spectra of LiNbO 3 and GaSb is reported. It proved high efficiency of this surface preparation method for extracting a bulk component of the XPS signal acquired from a crystal. In particular, two specific advantages of in situ scraping over a surface cleaning by Ar + ion bombardment have been underlined. Firstly, complete removal of surface adsorbed species (carbon and oxygen) and of the surface oxides. Secondly, despite mechanical damage of the crystal surface, the in situ scraping does not introduce surface defects that could influence the bulk XPS core-level spectra of the compounds studied (especially LiNbO 3 ). The bulk XPS data for GaSb, reported here, remain the first reference ones obtained with the use of this preparation method.