This article is the first one of a series devoted to the study of hydration processes in epoxy resins using infrared (FTIR) spectrometry, with a view to eventually determining the role of ambient H2O molecules in the degradation of these resins, particularly when they are exposed to irradiation. The starting experiment consists of recording spectra of thin films of these resins which allows us to propose a preliminary assignment of the bands of interest. The second experiment consists of heating these resins. As the main effect of a temperature elevation is to break hydrogen bonds, the analysis of the corresponding spectra enables us to more precisely assign bands which will be of importance in the hydration process. The third experiment consists of hydrating these resins in a humid atmosphere. The pressure of the water vapor of this atmosphere is directly measured in the IR spectra where the corresponding, extremely narrow bands are easily isolated. The analysis of the spectra obtained, after subtraction of these bands due to water vapor, allows us to determine the interaction configurations of H2O molecules which are embedded in the resins, that is, the various ways they establish or accept hydrogen bonds to or from hydrophilic groups.