Abstract: An axial flow fan, used for cooling the compressor and the condenser within the machine compartment of a refrigerator, is disclosed. This axial flow fan delivers an adequate volume of air to the machine compartment, and effectively reduces operational noise of the refrigerator. The axial flow fan has a hub mounted to the rotating shaft of a motor, with a plurality of blades regularly fixed around the hub, with the number of the blades being three and a diameter ratio of the inner diameter of the axial flow fan, equal to a hub diameter, to the outer diameter of the fan being set to 0.21˜0.25. In addition, the axial flow fan of this invention has a large sweep angle, a large pitch angle and a high camber ratio.