Metal-stimulated decomposition of sapphire surface at room temperature in a flux of electrons with energy of 70 keV. The stimulant used is an ensemble of crystalline islands of gold. It was first established that the presence of an ensemble of gold islands on the surface of sapphire significantly reduces substrate temperature and electron energy at which decomposition occurs surfaces. Etching pits form near gold islands and have an elongated shape with the following dimensions: length up to 1.2 μm, width up to 0.8 μm and average depth 20 nm. Maximum area the base of the islands increases from 0.6 to 1.8 μm2.