The growth conditions of thin films of Cu–In–Se–Te system fabricated by thermal evaporation and their composition, structural, optical, and electrical properties have been studied. When analyzing the optical absorption coefficient of the films, several energy gap discrete values appear: 0.86±0.04, 0.95±0.05, 1.26±0.06, 1.51±0.02, and 1.71±0.03 eV. Resistivities and mobilities varying in the ranges of 10−3 to 8 Ω cm and 0.2 to 28.6 cm2 V−1 s−1, respectively were found depending on growing conditions. The ‘‘as grown’’ samples were p type. The thermal treatments may change the type of conduction from p to n.