This fluid machine includes a motor housing, a rotating shaft which is inserted through the motor housing, an impeller which is mounted on a protruding portion of the rotating shaft, and a facing portion which faces the motor housing on a first end side in the axial direction. A first opening is provided on the first end side of the motor housing, a second opening is provided on a second end side of the motor housing, and an in-housing passage fluidly couples the first opening with the second opening. The fluid machine further includes an exhaust passage which is formed between the motor housing and the facing portion and which fluidly couples the first opening with external air, and a rotating blade which is disposed between the first opening and the exhaust passage, wherein the rotating blade is mounted on the rotating shaft and is rotatable with the rotating shaft.