Abstract: Peak shift and spectra distortion have been observed in XPS analysis of insulating specimens when the magnetic lens is activated.This has been attributed to the interaction between magnetic fields of the magnetic lens and low energy electrons from Al window of the twin anode X-ray source,which causes deflection of the low energy electrons,affects the quantity and distribution of the low energy electrons that reachec the sample,and so that affects the neutralization of positive charge on sample surface.It is also shown that the spectra differences caused by activating the magnetic lens and not may be used to study photoconductive phenomenon of insulating specimens.