A rotor core in which magnets are embedded is formed by stacking a plurality of steel sheets (1). The steel sheets (1) each have a disk-like shape and comprise: six magnet insertion holes (4) formed to allow permanent magnets to be inserted therein as a whole; circumferential bridge portions (5) which are formed, on the circumferential edge of the steel sheet (1), between the magnet insertion holes (4) and which connect outer diameter side steel sheets (3) in the circumferential direction; and radial bridge portions (6) formed between the magnet insertion holes (4). Each of the circumferentialbridge portions (5) and each of the radial bridge portions (6) have coined sections (5a, 6a), respectively, at which the sheet thicknesses are decreased and which are projected in arc-like shapes inthe sheet thickness direction. The coined sections (5a, 6a) having decreased sheet thicknesses suppress short-circuiting of magnetic fluxes between magnetic poles, and the arc-like shapes absorb elongation of the sections caused by coining, to suppress deformation of the steel sheets (1), and thereby, improve dimensional accuracy of the rotor core.