To reduce the wind loss of the rotor of a reluctance machine without using a segment filler by providing one piece of discoidal sheet which is constituted of an austenite phase part, which protrudes inside in a diameter direction, extends in an axial direction and is set to be a non-magnetic part and of a martensite phase part that is set to be a rotor pole part.

A discoidal rotor 17 where a plurality of thin electromagnetic steel sheets are stacked is fixed to an output axis 28 which is supported by a housing so that it can freely rotate. Thus, it integrally rotates with the output axis in the housing 12. Since the respective electromagnetic steel sheets 15 are complete disks, they substantially have high strength. The rotor 17 has a smooth surface for making window loss to be minimum and is provided with two pairs of facing rotor pole parts 19a, 19b and 20a and 20b. The respective rotor pole parts protrude outward in the diameter direction and they extend in the axial direction. When the rotor 17 rotates, clearances are given to the respective pairs of rotor pole parts and the respective pairs of stator poles and they are arrayed.