The results of depth profiling a four layered Si–O−Al thin film with different concentrations of elements in the layers are presented. Secondary-ion mass spectrometry (SIMS) and Rutherford backscattering (RBS) facilities are used to obtain the depth distributions of the element densities in the film. The data of analysis by the SIMS method are used as the initial concentration profiles in processing the Rutherford backscattering spectra using the SIMNRA program. As a result, a model film structure is constructed that describes the spectra of Rutherford backscattering obtained under various experimental measurement conditions, refines the results of analysis by the SIMS method and allows quantitative distributions with respect to the depth of the element concentration and the film density to be obtained.