Atomic absorption spectrometric investigation of manganese was carried out and a method was applied to the determination of manganese in steels, aluminium alloys and ferro-alloys. The optimum conditions for the determination of manganese were as follows : the wave-length 2795A, the current of hollow cathode lamp for manganese 60 mA, the slit width 0.05mm, air pressure 1.5 kg/cm^2 and acetylene pressure 0.5 kg/cm^2. Influences of coexisting elements and acids were also examined. The alloying elements and acids except a large amount of molybdenum did not interfere. A rapid method for the determination of manganese in steels, aluminium alloys and ferro-alloys without any preliminary separation of main elements was established. The method is very accurate and highly reproducible
