The vehicle-use generator driven by a vehicle engine at a rotating shaft thereof includes a rotor rotatably mounted to the rotating shaft, a stator fixedly located radially outward of the rotor, a cooling fan fixed to the rotor to rotate together with the rotating shaft in order to generate cooling air for cooling the stator, and a housing that houses the rotor and the stator and rotatably supports the rotating shaft. The housing is provided with ribs arranged in a circumferential direction of the rotating shaft so as to form cooling air outlet windows. The ribs are inclined with respect to a radial direction of the rotating shaft, and shaped such that widths of the ribs are gradually changed cyclically in the circumferential direction.