The first order semiconductor - metall phase transition with the lattice symmetry change from monoclinic to tetragonal and the conductivity jump of several orders of magnitude is observed in pure vanadium dioxide and the dioxide doped by varios impurities [I]. Transition temperature Ttfor pure VO2is 68°C and depends on the impurity. For example, the impurities which enter the insulating phase as pentavalent ions Nb5+[2] give rise to a decrease in metal-semiconductor transition temperature at low concentrations and the trivalent ions Cr3+, Fe3+[3,4] lead to an increase in Tt. In the latter case three different monoclinic phases are stabilized at a temperature below Tt. It has been already shown [5] that for double doping of vanadium dioxide by pentavalent Nb5+and trivalent Fe3+or Cr3+ions three semiconductor phases exist (MI, M2, M3) but the transition temperature decreases as the impurity concentration increases.