A thin Ag film, which was formed on an insulator substrate using the ion beam deposition method, has an insufficient structure by the electro-migration effect caused by the electric charge left in the film. In contrast to the ion beam deposition method, the result was satisfactory when direct current flows were applied to the film during its forming. The results of an SiO2 substrate were better than those for a Pyrex glass (PG) substrate. Using the direct current method, we formed a thin AE film onto an SiO2 substrate of 55 nm thickness and 1.0 nm native oxide. Experiments were carried out with a base pressure of 1.5 x 10(-7) Pa at room temperature (RT), and film was examined using X-ray diffraction (XRD), Auger electron spectroscopy (AES) and scanning tunneling microscopy (STM).