Abstract: The binding energy zero of an X-ray photoelectron spectrometer has been calibrated by the XPS signal of nickel 3d valence band, and the binding energy scale between 84 and 932 eV has been checked by the XPS peaks of gold and copper. In deing so the core level binding energies of several metals could be determined precisely. The CIS peak shift of adventitious carbon on metal surfaces to a value of leV has been found which might be attributed to the existence of different chemical states of carbon. By measuring the XPS intensities of some pure netil samples and using the theoretical values of photoionization cross section and escape depth, we obtained an apparent transmission function for our spectrometer, from which the relative atomic sensitivity factors of various elements could he derived. The results of our experimental measurements on several compound samples have shown that the accuracy within 20% could be reached by using these atomic sensitivity factors, which is much better than that obtained by using the theoretically calculated sensitivity factors onto our spectrometer. Although all of the above mentioned experiments have been done on an ESCALAB 5 type electron spectrometer, the same approach is supposed to be applicable to other typa XPS machines.