Temperature Programmed Desorption （TPD） and static chemisorption experiments were carried out ot find the best adsorbent for the economic separation of oxygen from air via the selective adsorption of highly dispersed metal crystallites. Co, Fe, Zn, Cu and Pt salts were impregnated into silica or alumina, calcined at 400 ℃ and reduced at 500 ℃ to prepare adsorbents for the separation of air. All the metals except for Pt desorbed oxygen very little, in spite of large amount of adsorption of oxygen because of the formation of stable oxide. The amount of adsorption of oxygen on Pt/γ-alumina increased up to 480 ℃, but started to decrease above 500 ℃. Maximum desorption rate of oxygen from Pt/γ-alumina was obtained between 500 ℃ and 600 ℃ when oxygen adsorbed on Pt/γ-alumina or oxygen atoms in surface platinum oxide compound were desorbed by raising the temperature. The amount of oxygen adsorbed on Pt/γ-alumina did not decrease much after the cyclic operation of adsorption and desorption.