An axial flow fan includes an impeller rotatable about a central axis with a plurality of rotor vanes, a motor that drives the impeller, a base portion that supports the motor, a housing that includes an intake vent, an exhaust vent, and an inner peripheral surface surrounding the impeller and the motor, and a plurality of stator vanes that respectively connects the base portion and the housing, wherein the inner peripheral surface includes a first inner peripheral surface arranged to increase a distance from the central axis toward the intake vent or the exhaust vent in an axial direction, and a recess provided between the first inner peripheral surface and a stator vane included in the plurality of stator vanes and facing the first inner peripheral surface. Thus, airflow is allowed to smoothly pass through the housing, resulting in a decrease in noise generated in the fan.