A non-aqueous electrolyte secondary battery that has a low initial resistance and an increase in resistance after charging and discharging is suppressed. The secondary battery includes a positive electrode, a negative electrode, and a non-aqueous electrolyte. The positive electrode includes a positive electrode active substance layer, which contains a lithium composite oxide having a layered structure. The lithium composite oxide is a porous particle. A surface of the porous particle includes a layer having a rock salt type structure. A thickness of the layer is not less than 5 nm and not more than 80 nm. A void ratio of the porous particle is not less than 15% and not more than 48%. The porous particle contains two or more voids having diameters that are at least 10% of the particle diameter of the porous particle. The surface of the porous particle includes a coating of lithium tungstate.