Atomic Layer Epitaxy (ALE) is a chemical vapor phase thin film deposition method which is based on saturative surface reactions. As the film is growing in a self-limiting manner ALE is a promising method to deposit thin, high-quality films for micro- and optoelectronics. In the present paper the deposition of different dielectric oxides, conducting oxides as well as nitrides is reviewed giving emphasis to precursors and their effect on growth mechanisms and film properties.