CdS ZnS superlattices (SLs), which contain 4 molecular layers of CdS and 16 molecular layers of ZnS, were successfully obtained on (100)GaAs substrates by means of atomic layer epitaxy (ALE) using a molecular beam epitaxy (MBE) system. It is suggested that each constituent layer has compressive and tensile strain. The layer configuration of the SL is in good agreement with the predesigned scheme, as shown by the results of X-ray diffraction analysis and transmission electron microscope pictures. This emphasizes that the ALE growth is effective in forming fine multilayer structures. The photoluminescence spectrum shows a dominant sharp peak at around 450 nm. The cathodoluminescence spectrum measured at room temperature also indicates a sharp peak at 453 nm. These emissions have originated from quantum levels formed in CdS well layers in the SL.