The phase formation sequences, intermediate and final products of aluminum nanopowder combustion are studied. The experiments were performed in the Budker Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, at the “Precision Diffractometry II” station (SR beamline No. 6 of the VEPP-3 electron storage ring). The main combustion product was found to be aluminum nitride. In the combustion of aluminum nanopowder aluminum ?-oxide is the first to form, and aluminum nitride arises next. The formation of aluminum nitride probably occurs by successive replacement of oxygen by nitrogen from the aluminum oxide. The use of synchrotron radiation with high photon flux made it possible to determine with moderate time resolution the sequence of stages of formation of crystalline products during combustion of the aluminum nanopowder