Thin Fe-57 films with the thickness of 120 nm have been prepared on glass substrates by using the ion-beam-assisted deposition technique. X-ray diffraction, electron microdiffraction and Mossbauer spectroscopy studies have shown that as-deposited films are in a stressful nanostructured state containing the nanoscaled inclusions of alpha-phase iron with the size of similar to 10 nm. Room temperature in-plane and out-of-plane magnetization measurements confirmed the presence of the magnetic alpha-phase in the iron film and indicated the strong effect of residual stresses on magnetic properties of the film as well. Subsequent thermal annealing of iron films in vacuum at the temperature of 450 degrees C stimulates the growth of alpha-phase Fe crystallites with the size of up to 20 nm. However, electron microdiffraction and Mossbauer spectroscopic data have shown the partial oxidation and carbonization of the iron film during annealing. The stress disappeared after annealing of the film. The magnetic behaviour of the annealed samples was characterized by the magnetic hysteresis loop with the coercive field of similar to 10 mT and the saturation magnetization decreased slightly in comparison with the alpha-phase Fe magnetization due to small oxidation of the film. (C) 2016 Elsevier B.V. All rights reserved.