Cupric oxide in thin film form is studied by infrared reflectance spectroscopy and is characterised by absorption bands at 480 and 540 cm(-1)(associated with transverse optical vibration modes) and at 600 cm(-1) (associated with longitudinal optical vibration mode). The modelisation of reflection spectra obtained when CuO oxide is present under different morphologies (inclusion, aggregate or outer layer of a multilayer system) predicts a shift of the band at 480 cm(-1) to 520 cm(-1). The experimental spectra obtained by copper oxidation confirm this trend and the influence of oxide film structure on the details of the spectra. Thus, infrared reflection spectroscopy is an appropriate method for the study and the understanding of complex structures such those developed during the oxidation of copper-nickel alloys.