We demonstrate using a scanning tunneling microscope reproducible and reversible recording and erasing of marks about 10 nm in size. Studies on both data storage devices and nanometer fabrication using a scanning tunneling microscope have been carried out, involving a variety of techniques and materials. However, most studies neglect erasing, despite the fact that erasing is a major requisite, as well as recording and reading. Using a thin layer of a vanadate glass deposited on vanadium bronze, beta-Na-x V2O5, has made it possible to record, erase, and read 10 nm level marks at ambient temperature and pressure. The main mechanism for reversible recording is sodium ion migration between the vanadium bronze crystal phase and the vanadate amorphous phase along the electric field. The organic medium of a hemiquinone molecule was proposed for higher recording speed.