The electronic properties of iron such as the band structure, work function, ionization potential and electron affinity, which determine its redox properties in solid state and liquid phase reactions, sensitively depend on the chemical, coordinating environment of the Fe species in question. Employing lab- and synchrotron-based photoemission and X-ray absorption spectroscopies together with complementary surface science methods, a comprehensive picture of the influence of the chemical environment on the electronic configuration in both valence band and conduction band regions of well-defined model systems including Fe atoms, ionic species, cluster, thin films, bulk will be derived.