To provide a cathode active material for a non-aqueous electrode rechargeable battery, with which it is possible to improve input/output characteristics, particularly by reducing resistance in a low SOC state in which DCIR increases, and to provide a manufacturing method for same. The cathode active material includes layered hexagonal crystal lithium nickel manganese composite oxide particles represented by the general formula (A): Li1+uNixMnyCozMtO2 (where 0≦u≦0.20, x+y+z+t=1, 0.30≦x ≦0.70, 0.10≦y≦0.55, 0≦z≦0.40, 0≦t≦0.10, and M is one or more elements selected from Al, Ti, V, Cr, Zr, Nb, Mo, and W), and further including Na, Mg, Ca and SO4, in which the total amount of Na, Mg and Ca is 0.01 to 0.1 mass %, the amount of SO4 is 0.1 to 1.0 mass %, and the ratio of the integrated intensity of the diffraction peak on plane (003) to that on plane (104) obtained by powder X-ray diffraction measurement using CuKα rays is 1.20 or greater.