Various Ge/Si layer structures (multilayers with 2 and 3 nm layer thicknesses, step function transition, and 1 nm Si imbedded between thick Ge layers) were depth profiled by using 1 keV He+ and Ar+ sputtering with angle of incidence of 83 degrees. The specimen was rotated during sputtering. The depth resolution determined on the step function transition weakly depended on the type of projectile used. Similarly there was not a strong deviation of depth profiles recorded on the imbedded Si layer (thickness 1 nm) if Ar+ or He+ projectile was used. In contrast a serious difference between the depth profiles measured by Ar+ and He+ sputtering was observed in the case of the multilayer systems. Based on these observations we concluded that the depth resolution (determined according to the standard) is not a sufficient characterization of a depth profiling device. It is proposed that depth profiling of some standardized multilayer structure, with layer thicknesses of 1-2 nm should also be added to the characterization of the sputtering device.