A secondary battery electrode, which is formed by stacking an electrode active material layer (I) containing spinel-structured lithium manganate as an electrode active material and an electrode active material layer (II) containing, as an electrode active material, a composite oxide represented by the following Chemical formula (1) in a thickness direction of the electrode, in which the electrode active material layer (I) is disposed in contact with a current collector, and an average particle diameter of the composite oxide is smaller than an average particle diameter of the spinel-structured lithium manganate. In such a way, it is possible to provide a secondary battery electrode capable of realizing a secondary battery excellent in both of a volumetric energy density and a volumetric output density. LiCovNiXMnYMZO2  (1)