The reduction of V2O5 under electron irradiation was studied by means of electron energy-loss spectroscopy, electron diffraction, and high-resolution imaging. The decrease of spectral intensity of O 1s excitations indicates a preferential removal of oxygen. The observed chemical shifts of the V 2p(3/2) and V 2p(1/2) peaks reveal that V5+ is reduced to V2+. Electron diffraction and high-resolution imaging show a structural change from the orthorhombic V2O5 to cubic VO. The beam induced reduction is compared with thermal decomposition Of V2O5.