Abstract: Indium-doped tin oxide In2Sn2O7 thin films were deposited on Superior w. Germany glass substrate by RF magnetron sputtering technique using a popular ceramic target with a combination of In 8 wt.% and SnO2 at a working pressure of 4.2H10-3 torr and radio frequency power of 100 W. These films were post-annealed at temperatures from 200-400°C for 1 h by both oxygen atmosphere and vacuum furnace. The resulting films were studied by X-ray diffraction reveals a poly crystalline structure of In2Sn2O7 phase formation with diffraction peaks related to the cubic phase structure of In2Sn2O7 according to JCPDS card 391058. The post-annealing atmospheric effects on micro structural, electrical and optical properties of In2Sn2O7 films were determined. The results assure that at a higher annealing temperature, the crystallinity of In2Sn2O7 films was enhanced, the optical transmittance of In2Sn2O7 thin films was increased over 90% at 650 nm in the oxygen atmosphere, compared to 85% at 680 nm for the same annealing temperature in the vacuum atmosphere. The resistivity of In2Sn2O7 thin films was increased with advanced annealing temperatures in the both vacuum and oxygen atmosphere furnace.