The authors report on a method of nanofabrication involving mechanical or/and electrical processes and atomic force microscopy (AFM). Nanostructures were formed on an oxidized silicon wafer by applying a load and/or electrical voltage using an electrically conductive diamond tip (approximately 45 nm radius) and the features of these nanostructures were investigated. AFM investigation showed that the height and morphology of the nanostructures were determined by the load and voltage. I/V Schottky curves were used to clarify the electric properties of the processed regions, which were shown to depend on the extent of local oxidation by mechanochemical and electrochemical reactions generated by tip sliding during the mechanical and/or electrical processing. In particular, the complex process including both mechanical and electrical processes enhances the local oxidation at a high load and voltage. (C) 2008 American Vacuum Society.