[en] The perovskite based SrFeO₃ and SrFe_0.5Nb_0.5O₃ materials have been synthesized by solid state reaction methods. The structural properties are investigated using a combination of X-ray diffraction and X-ray absorption fine structure spectroscopic techniques. From the Rietveld refinement of the X-ray diffraction data it has been observed that SrFeO₃ has a simple cubic perovskite structure, which is consistent with the previous literature results; whereas SrFe_0.5Nb_0.5O₃ shows a tetragonal structure within P4mm space group. X-ray absorption results demonstrate that the valence state of Fe in SrFeO₃ is (IV); however, it changes to (III) when 50% Nb⁵⁺ is substituted at the Fe sites. - Highlights: → Structural studies by employing XRD and XANES spectroscopic techniques. → Rietveld refinement confirmed SrFeO₃ has cubic structure, space group Pm-3m. → It is revealed that SrFe_0.5Nb_0.5O₃ has tetragonal structure, in P4mm space group. → From XANES results it is observed that Fe has valence state of (IV) in SrFeO₃. → Doping of 50% Nb⁵⁺ at Fe sites, changes Fe valence to (III) in SrFe_0.5Nb_0.5O₃.