Decomposition of CpCuPEt3 (Cp=NNN(η5-C5H5)) and MOCVD of Cu films from CpCuPEt3 have been investigated in the frame of an ongoing project on the processing of Cu-containing coatings. The behaviour of CpCuPEt3 vapours under heating conditions was studied by in situ mass spectrometry. It was established that this compound is monomeric in gas phase. Its decomposition mechanism on hot surface was proposed. From mass spectroscopy experiments, it was established that decomposition in vacuum begins at 150 °C with evolution of PEt3. Beyond 270 °C, formation of cyclopentadiene is observed, indicating that a change in decomposition mechanism occurs. The saturating vapour pressure of CpCuPEt3 was estimated through static method, in order to optimize transport conditions and to control the molar fraction of the precursor in the gas phase. Finally, growth rate and microstructure of MOCVD processed Cu films from CpCuPEt3 have been investigated.