Abstract: A positive electrode active material and a non-aqueous electrolyte cell which uses the positive electrode active material. The cell has a high discharge voltage without lowering the capacity and superior charging/discharging characteristics. To this end, the positive electrode active material contains a compound represented by the general formula LixMnyFe1-yPO4, wherein 0<x≦2 and 0.5<y<0.95, or a compound represented by the general formula LixMnyA1-yPO4, where 0<x≦2 and 0<y<1 and wherein A is a metal element selected from among Ti, Zn, Mg and Co or plural metal elements selected from among Ti, Fe, Zn, Mg and Co.