Abstract: An axial fan includes an impeller that is provided with a blade that rotates around a central axis extending in a vertical direction, a motor unit that rotates the impeller, and a housing that is provided closer to a radially outer side than the impeller and surrounds the impeller. The impeller is further provided with an assist blade that protrudes at least in an axial direction from a radially outer end portion of the blade and extends in a circumferential direction. The assist blade is provided with a variable width portion at which an assist blade width between the blade and a tip end portion of the assist blade in a direction in which the assist blade protrudes decreases toward a rear side in a rotation direction from a front side in the rotation direction.