A rotor for rotating electrical machine comprising: a cylindrical rotor core formed by laminating magnetic steel plates (16, 16a) in an axial direction and integrally connecting them and having therein magnetic insertion holes (12, 24, 26) for inserting permanent magnets inside, wherein the magnet insertion holes (24, 26) are formed extending in the axial direction of a core inner section in the vicinity of an outer peripheral surface of the rotor core, and with opening formed in axial direction end sections of the rotor core, and a plurality of magnetic steel plates (16, 16a), including magnetic steel plates at outermost sides in the axial direction in which the openings are formed, are fixed by welding at inner wall surface of the magnetic insertion holes, and a welded section of the inner wall surface of the magnetic insertion holes is only provided on both end sides in the axial direction of the rotor core, a plurality of permanent magnets which are inserted and disposed in the magnetic insertion holes (24, 26); a rotor shaft which the rotor core is fixed to the outer periphery thereof; and at least one end plate arranged in contact with at least one of the end surface (11a, 11b) of the rotor core in the axial direction, wherein the endplate is made smaller in diameter than the rotor core so that - a pressing force does not act on the outer peripheral section of the magnetic steel plates which construct the core and - the plurality of magnetic steel plates (16, 16a), including the magnet steel plates positioned outermost in the axial direction, are connected at the outer peripheral sections by the welded sections. a cylindrical rotor core formed by laminating magnetic steel plates (16, 16a) in an axial direction and integrally connecting them and having therein magnetic insertion holes (12, 24, 26) for inserting permanent magnets inside, wherein the magnet insertion holes (24, 26) are formed extending in the axial direction of a core inner section in the vicinity of an outer peripheral surface of the rotor core, and with opening formed in axial direction end sections of the rotor core, and a plurality of magnetic steel plates (16, 16a), including magnetic steel plates at outermost sides in the axial direction in which the openings are formed, are fixed by welding at inner wall surface of the magnetic insertion holes, and a welded section of the inner wall surface of the magnetic insertion holes is only provided on both end sides in the axial direction of the rotor core, a plurality of permanent magnets which are inserted and disposed in the magnetic insertion holes (24, 26); a rotor shaft which the rotor core is fixed to the outer periphery thereof; and at least one end plate arranged in contact with at least one of the end surface (11a, 11b) of the rotor core in the axial direction, wherein the endplate is made smaller in diameter than the rotor core so that - a pressing force does not act on the outer peripheral section of the magnetic steel plates which construct the core and - the plurality of magnetic steel plates (16, 16a), including the magnet steel plates positioned outermost in the axial direction, are connected at the outer peripheral sections by the welded sections. - a pressing force does not act on the outer peripheral section of the magnetic steel plates which construct the core and - the plurality of magnetic steel plates (16, 16a), including the magnet steel plates positioned outermost in the axial direction, are connected at the outer peripheral sections by the welded sections.