I have reassembled a whole inverse photoemission system (IPES) system and performed calibration on the optical system. This system has a resolution of 0.32 eV for first-order diffraction of Helium I radiation, and 0.14 eV for first-order diffraction of Lyman α radiation. The overall resolution is 0.54 eV at 22.28 eV beam energy determined by the Fermi edge of a thick gold film, primarily from spot size and energy spread of electron beam. The methods of improving the resolution are discussed. The IPES experiments on sputtered Ni(111) and on oxidized Ni(111) were conducted. Nickel has a peak around 0.5 eV, which is ascribed to d band above the Fermi energy (EF). The oxidized nickel has one wide peak around 3 ~ 4 eV relative to EF and another peak around 13 eV, similar to the characteristics of nickel oxide in the literature.