CuAlSe2 and CuAlTe2 thin films have been obtained by annealing, in an open reactor, thin layers of the constituents deposited by evaporation in the stoichiometric ratio. It is shown that an annealing of half an hour at 673 K (CuAlTe2) and 717 K (CuAlSe2), under an argon flow, allows to achieve CuAlTe2 and CuAlSe2 chalcopyrite thin films. However, even after optimization of the technique, there is some oxygen contamination. It is shown that this contamination is not only related to Al but also to Te in the case of CuAlTe2. This justifies the higher discrepancy between single crystal and CuAlTe2 thin film performances. This is related to the contamination, not only of the grain boundary, which is the case of CuAlSe2, but also of the crystallite induced by Te. On the other hand, structural and optical properties of CuAlSe2 films are very similar to those measured on single crystals and epitaxial layers.