a rotating electric machine of a third embodiment of the present invention will be described with fig5 and 9 fig5 is a cross sectional view of the rotating electric machine of the third embodiment of the present invention fig6 is an exploded cross sectional view of the rotating electric machine of the third embodiment of the present invention in the rotating electric machine of the third embodiment of the present invention a housing 110 has a double cylinder structure of an inner cylinder 111 and an outer cylinder 112 an outer diameter surface 111 a of the inner cylinder 111 and an inner diameter surface 112 a of the outer cylinder 112 are inclined in the axial direction and the outer diameter surface 111 a of the inner cylinder 111 includes a groove that forms a cooling liquid passage 113 since the outer diameter surface 111 a of the inner cylinder 111 is inclined in the axial direction a cross sectional area of the cooling liquid passage 113 decreases gradually from the left to the right in fig5 due to this by providing a cooling liquid inlet 115 a to a passage 113 a having the largest cross sectional area and providing a cooling liquid outlet 115 b to a cooling liquid passage 113 c having the smallest cross sectional area influence of a temperature rise of the cooling liquid can be removed like in the rotating electric machine of the second embodiment of the present invention moreover an outer diameter of the inner cylinder 111 at a position in contact with the.