In this investigation ZnFe2O4 thin films were fabricated by RF magnetron sputtering and the magnetic behavior was examined under the influence of the growth conditions in three types of atmospheres, using near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and vibrating sample magnetometry (VSM). XPS revealed that films under an Ar/O2 ratio 1:2 and 2:1 have Fe/Zn atomic ratios similar to the Fe/Zn stoichiometric composition; while the films deposited in pure Ar atmosphere, showed a formation of Fe ions (Fe0) reduced by Ar ion sputtering. VSM revealed an enhancing of the saturation magnetization for the ZFO in thin films unlike the samples in bulk, suggesting that Fe ions migrate to A sites and the interaction JAB dominates the magnetic properties instead of JBB interaction. Display omitted •ZFO thin films were growth by RF magnetron sputtering system, using several Ar/O2 ratios as working gas pressure.•The presence of Fe0 is favored when the ZFO thin films are deposited in pure Ar atmosphere.•The ZFO thin films showed an inversion degree of the surface structure, determined by XPS.•Fe ions migrate to A sites in the structure of ZFO film, enhancing the magnetic response in comparison with the ZFO in bulk.