In this paper, CuInSe2 thin film was prepared by use of the co-evaporation method with the variation of the substrate temperature in the range of 100℃ to 400℃. The film was annealed at 300℃ for an hour in a vacuum chamber at 3×10-4 Pa. After annealing, the thin film prepared at the substrate temperatures of 100℃ and 200℃ was observed. The XRD (x-ray diffraction) pattern of sample prepared at 100℃ showed the single phase formation of CuInSe2. However, at 200℃, there was no apparent difference in the XRD pattern except a variation in the intensity of the peak. As the annealing treatment of substrate improved the crystal structure of the film, it affected to the increase of an electron mobility, resulted in an increase in conductivity and a decrease in resistance. As a results, when the substrate temperature was at 200℃ and 300℃, the sheet resistance was 1.534 n/and 1.554 n/, respectively, and the resistivity was 1.76×10-6 n·㎝ and 1.7210-6 n·㎝, respectively. From the absorption spectrum measurements, there was no variation between the before and after annealing conductions. And it means that the annealing step does not affect the thickness of the thin film.