Abstract: The effect of annealing temperature on the optical and surface properties of Ta₂O₅ films has been investigated. The thin films were prepared on quartz substrate by electron beam evaporation technique and annealed at 200℃, 400℃ and 600℃ respectively. The transmissibility of the films was measured by spectrograph, and the variation of refractive index and extinction coefficient were obtained by inversion calculation. The surface properties of the films were characterized by X-ray diffraction and atomic force microscopy. The results show that the maximum value of the transmittance curve of the films increase significantly with the increase of annealing temperature. With the increase of annealing temperature, the refractive index and extinction coefficient of Ta₂O₅ film increase gradually, while the surface roughness of the film decreases, and the surface of films becomes dense. Both deposited and annealed films are amorphous. This study provides experimental data for further improving the performance of Ta₂O₅ thin films.