PURPOSE: To obtain the excellent charging and discharging capacity and the excellent cycle characteristic by using lithium-manganese compound oxide, to which the specified processing is performed, as the positive electrode active material of the non-aqueous solvent lithium secondary battery.

CONSTITUTION: This non-aqueous solvent lithium secondary battery is provided with a positive electrode, in which lithium-manganese compound oxide is used as the positive electrode active material, a negative electrode made of lithium, a negative electrode made of lithium alloy, a negative electrode made of the carbonaceous material, in which lithium or lithium alloy is carried and which can store and discharge lithium ion, and the non-aqueous electrolyte. As the positive electrode active material, the lithium-manganese compound oxide, which is heated, washed and dried under the existence of carboxylic acid solution at 4.75≤pKa<4.83 of acid dissociation constant at 25°C, is used. As the lithium- manganese compound oxide, Li2MnO3 is especially desirable.