  The technological conditions of oxygen content variation in epitaxial
La0.7Sr0.3MnO3-{\delta} films and the peculiarities of change of their
transport characteristics were investigated. The films were grown onto single
crystal SrTiO3 substrates by an enhanced method of dc magnetron sputtering of a
ceramic target. It was revealed, that the oxygen content of the film material
with initially strong deviation from stoichiometric composition ({\delta}>0.06)
changes easily in both directions at temperatures Tp >=870 K, and the result of
the oxygen content variation can be well controlled via changes of conductivity
minimum temperature (Tm). The particularities of indirect accurate control of
the oxygen content in the film are described. The existence of oxygen-excessive
composition of the film is in principal agreement with the known phase diagrams
for a powder samples. It was revealed, the oxygen-excessive content of the film
causes the increase of free charge carriers concentration and the decrease of
the film conductivity in ferromagnetic state. It is shown, that the
oxygen-deficient films can demonstrate the same peculiarity of magnetotransport
properties as the films with a deviation from stoichiometric content in cation
composition.
