There is provided a method for inspecting a laminated iron core structured by laminating a plurality of iron core pieces-having a predetermined shape and including therein a cooling flow path allowing refrigerant to flow therethrough, the refrigerant being supplied and discharged through openings formed at different positions. The method includes arranging a light projecting part and a light receiving part of a photosensor in the openings of the cooling flow path, respectively, and detecting light from the light projecting part by the light receiving part to thereby inspect a penetrating state of the cooling flow path.