A method is described for preparing graphite films down to about 2nm in thickness. First, a suspension of small flakes in ethylene dichloride is prepared by repeated cleavage of a graphite crystal. This is then used to prepare a relatively thin film of graphite which is applied to grids previously coated with a holey carbon film. Fragments of tungsten oxide crystals are placed on the grid which is then exposed in the electron microscope to an electron beam of high intensity. As the result of an apparent reaction between the tungsten oxide and the carbon, the graphite film is etched, thereby producing a film which is both much thinner and cleaner than the original. The thickness of films prepared in this way has been estimated and their characteristics described. A brief account is given of the use of such a film using ferritin as a test object.