The main objective of this study is to find out to what extent different preparation conditions and deposition techniques influence the SiO2 thin film microstructure, and therefore water incorporation which could take place during the deposition process or/and after exposure of the film to the atmosphere. SiO2 thin films were deposited by classical e-gun evaporation and ion-plating techniques. The results gathered so far revealed that absorption-reflection FTIR spectroscopy performed at near grazing incidence angle conditions (NGIA) is a fast and reliable way for qualitative water detection. By applying of appropriate standards, AES could be satisfactorily used for the prediction of incorporated water in the him.