[en] The work function is quite sensitive to the change of surface electronic properties of solid materials. Recently, the present authors have developed experimental systems which enable to measure the work function of solid materials under various circumstances. Pellets of lithium oxide ceramics, Li₄SiO₄, Li₂ZrO₃, Li₂TiO₃, Li₂O and LiAlO₂, were employed and installed in a ''high temperature Kelvin probe'' to measure the work function of these materials at elevated temperatures as well as under controlled chemical compositions of the surrounding gas phase. Further work is under way in which the effect of beam irradiation, either by H⁺ (H₂⁺) or He⁺ ions or by neutrons, on the work function is being investigated. (orig.)