A method of manufacturing a nonvolatile memory device having a laminated structure in which a first magnetic material layer, a tunnel insulator film, and a second magnetic material layer are sequentially laminated, in which information is stored when an electric resistance value changes depending on a magnetization reversal state is disclosed. The method includes the steps of: sequentially forming the first magnetic material layer, the tunnel insulator film, and the second magnetic material layer; forming a mask layer on the second magnetic material layer; oxidizing a part uncovered by the mask layer of the second magnetic material layer; and reducing the oxidized part of the second magnetic material layer.