The spin resolved electronic structure of ultra-thin Fe films on Cu(100) was investigated using spin polarized angle resolved photoemission spectroscopy. All exchange splitting of the Fe ∆s band of 2.5 eV is observed for photon energies between 20 and 30 eV. ∆ peak at 6 eV binding energy which has been previously identified as a many-electron resonance was observed only after contamination of the films with oxygen. In addition, the spin dependent attenuation lengths for electrons in Fe were measured at 11, 19, and 40 eV above Ef. The attenuation length for the minority spin electrons was found to be shorter than that of the majority spin electrons. The difference between the two attenuation lengths was shown to increase at low energy. Short attenuation lengths of ≃3 monolayer were measured at II eV. The large increase of the attenuation length at low energy which is expected from the “universal curve” is not observed in Fe.