A numerical method is proposed for the non-destructive restoration of the depth—concentration profiles for four components, based on the angular distribution of XPS intensities. Calculations performed for a number of model systems demonstrated that ratios of concentrations obtained by using simplified procedures, i.e. from relative XPS intensities for a single escaping angle, led to large errors (up to 200%) for the upper surface layer. A number of restored profiles are presented using experimental angle-resolved XPS data for samples containing 3–4 components.