In this work studied The surface characterization of SiO2 nano film in the thickness range (2.3- 11.5) nm by using atomic force microscopy . SiO2 nano film growth on Silicon (100) p-type substrates , by using the anodic oxidation technique using (%75H2O+%25 isopropanol ) solution containing 0.1N KNO3 as supporting electrolyte. The chemical analysis of the surface of SiO2 has been done by (EDAX) shows the presence of O and Si elements, The films thickness has been found that is increases as formation potential increases. The (AFM) is used to study the nanotopography of SiO2 film . However it has been found that all of the following characteristics ,the nanotopography of the SiO2 nano film , root mean square RMS surface roughness of the SiO2 nano film , grain area , grain volume and grain length increases with the increase of SiO2 nano thickness. .