A rotary electric machine comprising: a stator; a rotor having a rotor iron core disposed on an inner perimeter side of a stator iron core of the stator; a rotating shaft configured to rotate the rotor iron core; a bearing configured to rotatably support the rotating shaft; a cooling fan provided on the rotating shaft; a housing configured to contain the stator iron core and the rotor iron core, wherein the cooling fan comprises a main plate, vanes provided on a surface of the main plate such that the vanes extend in a radial direction of the rotor iron core, the surface being opposite to the housing, and a side plate connected to the vanes, the side plate being provided such that the side plate runs straight along an inclined straight part of the main plate when seen in a longitudinal cross section; the main plate is disposed on the rotating shaft such that a space formed by the housing is partitioned into a first region in which the stator and the rotor are provided and a second region on an opposite side of the first region through the cooling fan in which an air inlet port and a dust outlet port are provided, cross sectional form of the main plate along a longitudinal direction of the rotating shaft is inclined so as to approach an inner wall of the housing, and an outer edge part of the main plate is formed nearly perpendicularly to the rotating shaft; the housing is provided with the air inlet port in a region in which the side plate is projected in a longitudinal direction of the rotating shaft onto the housing; and an angle φ formed by the inclined straigth part of the main plate and the side plate is greater than an angle of zero degree, and a spacing between the main plate and the side plate is formed such that the spacing is wider toward an inner diameter side. a stator; a rotor having a rotor iron core disposed on an inner perimeter side of a stator iron core of the stator; a rotating shaft configured to rotate the rotor iron core; a bearing configured to rotatably support the rotating shaft; a cooling fan provided on the rotating shaft; a housing configured to contain the stator iron core and the rotor iron core, wherein the cooling fan comprises a main plate, vanes provided on a surface of the main plate such that the vanes extend in a radial direction of the rotor iron core, the surface being opposite to the housing, and a side plate connected to the vanes, the side plate being provided such that the side plate runs straight along an inclined straight part of the main plate when seen in a longitudinal cross section; the main plate is disposed on the rotating shaft such that a space formed by the housing is partitioned into a first region in which the stator and the rotor are provided and a second region on an opposite side of the first region through the cooling fan in which an air inlet port and a dust outlet port are provided, cross sectional form of the main plate along a longitudinal direction of the rotating shaft is inclined so as to approach an inner wall of the housing, and an outer edge part of the main plate is formed nearly perpendicularly to the rotating shaft; the housing is provided with the air inlet port in a region in which the side plate is projected in a longitudinal direction of the rotating shaft onto the housing; and an angle φ formed by the inclined straigth part of the main plate and the side plate is greater than an angle of zero degree, and a spacing between the main plate and the side plate is formed such that the spacing is wider toward an inner diameter side.