The LaB6(001) clean surface and its initial oxidation have been studied by UPS, XPS, and work‐function measurements. For the clean surface, a so‐called surface state has been found, and a work function of 2.4±0.1 eV has been measured. The surface state disappears by an oxygen exposure of ∼7 langmuir (L), and the work function increases up to 4.0±0.1 eV. This initial oxidation is not a simple oxygen‐adsorption process but proceeds with the formation of a surface oxide or oxides.