A three-phase rotating electrical machine includes a stator (2) including a stator core (21) provided with a plurality of teeth (23) and a plurality of slots (24), and winding (27), the three-phase rotating electrical machine including a rotor (3) including a rotor core (31) and a north magnetic pole (33N) and a south magnetic pole (33S), the three-phase rotating electrical machine including a fractional slot configuration, the rotor core including a north magnetic pole acting portion (34N), a south magnetic pole acting portion (34S), magnetic pole boundaries (35, 36, 361, 362) dividing the north magnetic pole acting portion and the south magnetic pole acting portion in the circumferential direction, and magnetic resistance portions (41, 42, 43, 441-444, 451-454, 461-464, 471-474), the magnetic resistance portion restricting the magnetic flux from passing through.