A rotor core composed of a laminated steel body formed by axially laminating a plurality of magnetic core plates one above another, the core plates extending in a direction orthogonal to a vertical center axis, the rotor core comprising: a plurality of magnetic pole portions arranged along a circumferential direction with magnet insertion spaces defined between adjoining magnetic pole portions , each of the magnetic pole portions including a pair of circumferential end surfaces facing toward the magnet insertion spaces and a radial end surface facing toward a space existing radially outward of each of the magnetic pole portions , wherein at least some of the core plates include claws protruding from the magnetic pole portions in the circumferential direction and outer connection portions arranged radially outward of the claws to interconnect the magnetic pole portions adjoining to each other, and the magnet insertion spaces are interposed between the circumferential end surfaces of the magnetic pole portions and positioned radially inward of the claws , wherein the pair of the claws is arranged radially outward of each of the magnet insertion spaces , wherein a first space exists between the pair of the claws at a radial outer side of each of the magnet insertion spaces , each of the outer connection portions is positioned radially outward of the first space , and second spaces exist between the claws and the outer connection portions , characterized in that the claws have slant surfaces coming closer to base end portions of the claws as the slant surfaces extend radially outward, the second spaces existing between the slant surfaces and radial inner surfaces of the outer connection portions . a plurality of magnetic pole portions arranged along a circumferential direction with magnet insertion spaces defined between adjoining magnetic pole portions , each of the magnetic pole portions including a pair of circumferential end surfaces facing toward the magnet insertion spaces and a radial end surface facing toward a space existing radially outward of each of the magnetic pole portions , wherein at least some of the core plates include claws protruding from the magnetic pole portions in the circumferential direction and outer connection portions arranged radially outward of the claws to interconnect the magnetic pole portions adjoining to each other, and the magnet insertion spaces are interposed between the circumferential end surfaces of the magnetic pole portions and positioned radially inward of the claws , wherein the pair of the claws is arranged radially outward of each of the magnet insertion spaces , wherein a first space exists between the pair of the claws at a radial outer side of each of the magnet insertion spaces , each of the outer connection portions is positioned radially outward of the first space , and second spaces exist between the claws and the outer connection portions , characterized in that the claws have slant surfaces coming closer to base end portions of the claws as the slant surfaces extend radially outward, the second spaces existing between the slant surfaces and radial inner surfaces of the outer connection portions . <EOS>