In this study nickel ferrite thin films have been grown on strontium titanate-100 single crystal substrate by using RF magnetron sputtering. To investigate the electronic structure of nickel ferrite film, X-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy were employed. In the X-ray photoelectron spectra of Fe 3p, the presence of the valence states Fe2+ and Fe3+ was evidenced; also, Ni2+ and Ni3+ were identified in the Ni 3p spectra. The atomic ratio of 2.01 was found, which is agreeing to the nominal atomic ratio. By reflection electron energy loss measurements found a band gap between 1.77 eV. The magnetic properties were analyzed by vibrating sample magnetometry, indicating in-plane easy magnetization.