The first groove portion 44a is continuous from the refrigerant introduction groove 43. The first groove portion 44a is an annular concave groove having a radius D1 larger than the length from the center CL of the rotor 51 to the inner diameter side apex portion 25d of the first refrigerant flow path hole 25, smaller than the length form the center CL of the rotor 51 to the first refrigerant discharge hole 42a, and smaller than the length from the center CL of the rotor 51 to inner diameter side apex portions 26d and 27d of the second refrigerant flow path hole 26 and the third refrigerant flow path hole 27. Therefore, the first groove portion 44a supplies the refrigerant supplied from the refrigerant flow path 12 to the first refrigerant flow path hole 25 and does not directly supply the refrigerant to the first refrigerant discharge hole 42a, the second refrigerant flow path hole 26, and the third refrigerant flow path hole 27. The flow of the first refrigerant in the vicinity of the first groove portion 44a will be specifically described. The refrigerant flowing through the refrigerant flow path 11 is introduced from the refrigerant introduction groove 43 to the first groove portion 44a as indicated by an arrow T0 in FIGS. 2 and 4, and then the refrigerant is supplied from the first groove portion 44a to the first refrigerant flow path hole 25 of the rotor core 20. As indicated by an arrow T1 in FIG. 4, the refrigerant supplied to the first refrigerant flow path hole 25 flows through the first refrigerant flow path hole 25 in the axial direction from the first end plate 40a side to the second end plate 40b side, thereby cooling the magnet 31 disposed in each magnetic pole portion 30.