The VB and the core levels of clean and oxygen exposed bulk samples of La and LaNi 5 were investigated by means of photoelectron spectroscopy using MgKα (XPS) and HeII (UPS) radiation. The HeII VB of La only shows 1.3 eV FWHM. The VB of LaNi 5 is mainly derived from the VB of Ni. The low binding energy satellite of the La3d core level (4f 1 final state) is much stronger in LaNi 5 than in La, reflecting the better screening of the 3d core-hole by filling of f states. The spectra indicate clearly that La oxidizes and not Ni upon the exposure of LaNi 5 to small amounts of oxygen.