X-ray photoelectron spectroscopy (XPS) is known to be one of the relatively low destructive surface analysis techniques. Surface changes of the samples during the XPS measurements are often observed. This change called surface degradation has at present no standard to determine its extent. In this report, we have carried out several “round-robin” tests to investigate this phenomena, and the relative X-ray dose parameter that represents the intensity of the Ag_3d5/2 peak multiplied with the measurement time was found to be important in the XPS spectra analysis. This article describes the methods for the evaluation of the surface degradation of the samples during the XPS measurements.