The aim of this study is to develop an inexpensive method for preparing transparent and heat insulating tin oxide film. Antimony-doped tin oxide (ATO) thin films have wide variety of technical applications, such as high transmission of visible light and heat insulated coatings. Films were formed by the dip-coating of this colloidal suspension. The structure and morphology of these films were analyzed using XRD and SEM analysis. The optical properties of the ATO thin films were investigated using a UV–VIS spectrophotometer. The heat insulating performance was evaluated using Halogen lamps to irradiate a film coated glass which cover on wooden box for two hours. The results of this study indicate that only the SnO phase (tetragonal rutile structure) appeared in X-ray diffraction, and the Sb dopant does not from a second phase. However, the crystallinity of the SnO structure is impaired by the presence of antimony. For the heat insulating performance the ATO coated glass achieves better heat insulation than that of bare glass.