A rotor structure of a motor comprising: a rotor core formed by laminating a plurality of laminated steel plates; a permanent magnet (18, 19) disposed in the rotor core; and end plates (25, 26) fastened to opposite end portions of the rotor core, respectively, wherein first holes of a first diameter and second holes of a second diameter that is larger than the first diameter are perforated alternately in a circumferential direction at equal intervals in each of the laminated steel plates, the end plates (25, 26) have holes (31, 32) through which fastening members are inserted, the fastening members including first fastening members and second fastening members, the end plates (25, 26) are respectively fixed to the end portions of the rotor core by the fastening members inserted to the holes (31, 32), and the rotor core is divided into first laminated portions in which the plurality of the laminated steel plates including the laminated steel plates (14a, 14b) adjacent to the end plates (25, 26) are laminated, and a second laminated portion interposed between the first laminated portions, in the second laminated portion, the plurality of the laminated steel plates including the laminated steel plates (14c, 14d) adjacent to the first laminated portions are laminated and rotated with respect to the plurality of the laminated steel plates in the first laminated portions in such a manner that the second holes in the second laminated portion are connected to the first holes in the first laminated portions, which first holes are connectively arranged in a longitudinal direction of the rotor in the first laminated portions, characterized in that the end plates (25, 26) are respectively fixed to the end portions of the rotor core by the fastening members inserted to the holes (31, 32) of the end plates (25, 26) and the first holes of the plurality of the laminated steel plates of the first laminated portions including the laminated steel plates (14a, 14b) adjacent to the end plates (25, 26), and one of the end plates (25, 26) and the adjacent first laminated portion are held by bearing seats (Z1, Z2) of the first fastening members and the other one of the end plates (25, 26) and the adjacent first laminated portion are held by bearing seats (Z1, Z2) of the second fastening members. a rotor core formed by laminating a plurality of laminated steel plates; a permanent magnet (18, 19) disposed in the rotor core; and end plates (25, 26) fastened to opposite end portions of the rotor core, respectively, wherein first holes of a first diameter and second holes of a second diameter that is larger than the first diameter are perforated alternately in a circumferential direction at equal intervals in each of the laminated steel plates, the end plates (25, 26) have holes (31, 32) through which fastening members are inserted, the fastening members including first fastening members and second fastening members, the end plates (25, 26) are respectively fixed to the end portions of the rotor core by the fastening members inserted to the holes (31, 32), and the rotor core is divided into first laminated portions in which the plurality of the laminated steel plates including the laminated steel plates (14a, 14b) adjacent to the end plates (25, 26) are laminated, and a second laminated portion interposed between the first laminated portions, in the second laminated portion, the plurality of the laminated steel plates including the laminated steel plates (14c, 14d) adjacent to the first laminated portions are laminated and rotated with respect to the plurality of the laminated steel plates in the first laminated portions in such a manner that the second holes in the second laminated portion are connected to the first holes in the first laminated portions, which first holes are connectively arranged in a longitudinal direction of the rotor in the first laminated portions, characterized in that the end plates (25, 26) are respectively fixed to the end portions of the rotor core by the fastening members inserted to the holes (31, 32) of the end plates (25, 26) and the first holes of the plurality of the laminated steel plates of the first laminated portions including the laminated steel plates (14a, 14b) adjacent to the end plates (25, 26), and one of the end plates (25, 26) and the adjacent first laminated portion are held by bearing seats (Z1, Z2) of the first fastening members and the other one of the end plates (25, 26) and the adjacent first laminated portion are held by bearing seats (Z1, Z2) of the second fastening members.