Abstract <p>Nanostructured materials, due to the production conditions and structural features, are nonequilibrium formations. The structure and its thermal stability, as well as various properties of nanomaterials, depend significantly on the method of external action initiating the passing of many processes. The paper presents the results obtained by studying the thermal stability of the structure and phase composition of a nanocrystalline titanium film formed on a substrate by vacuum plasma (argon plasma) electric arc sputtering of a cathode made of technically pure grade VT1-0 titanium. The film structure was thermally exposed by pulsed electron beam irradiation (10 and 15 J/cm², 17 keV, 200 μs, 0.3 s^–1, 3 pulses) in argon at a pressure of 0.02 Pa. Prior to irradiation, the titanium film was found to be a single phase (α-Ti) material; it has a columnar structure with 1.3–2.7 nm crystallites forming columns. The irradiation of the film with a pulsed electron beam is accompanied by the formation of a surface layer containing titanium oxide nanoparticles (2.6–8.3&#xa0;nm). It was observed that the relative content of these nanoparticles increased with increasing electron beam energy density.</p>