Abstract: In this study, a low cost simple improved system of Close-Spaced Vapour Transport (CSVT) technique consisting of using a horizontal and open reactor was designed; thin films of CuInSe2 were successfully prepared. Unlike the configuration with closed reactor, the present design does not require vacuum, a continuous argon flow in the reactor is enough during the films growth. Analysis by X-ray diffraction made it possible (I) to study the crystalline structure of the deposited CuInSe2 thin films (ii) to determine the various crystallization planes and (iii) to detect various involved phases. It was found that all deposited thin films have polycrystalline and chalcopyrite structures. Moreover, the thin films deposited at 550°C present a preferential (112) orientation. A scanning electron microscope associated with an energy dispersion spectrometer was used to study the morphology of the films surface and to determine the chemical composition of their constituents. The analysis of the results not only confirmed the above thin films polycrystallinity but also showed the quasi-stoechiometry of the thin films with a Cu/In ratio varying from 0.91 to 1.10.