According to one embodiment, a magnetoresistive element comprises a storage layer having perpendicular magnetic anisotropy with respect to a film plane and having a variable direction of magnetization, a reference layer having perpendicular magnetic anisotropy with respect to the film plane and having an invariable direction of magnetization, a tunnel barrier layer formed between the storage layer and the reference layer and containing O, and an underlayer formed on a side of the storage layer opposite to the tunnel barrier layer. The reference layer comprises a first reference layer formed on the tunnel barrier layer side and a second reference layer formed opposite the tunnel barrier layer. The second reference layer has a higher standard electrode potential than the underlayer.