This is a review of our studies on an application of the RHEED (reflection high energy electron diffraction) intensity oscillation to fabricate well defined metallic superlattices by UHV evaporation. First an observation of the RHEED intensity oscillations of the growth of Ag on Ag (001) is described to get a physical image of the phenomena. Next a result of a fabrication of metallic superlattices by counting the RHEED oscillations are shown. Problems of the technique like `phase shift` and peculiar initial growth process will be shown. Finally, a trial to avoid these problems changing combination of the materials and sequence of the depositions are introduced.