An axial fan comprising: - a hub; - a plurality of blades (12, 30) arranged in a circumferential direction of the hub; - a cutout in a rear edge part of each of the plurality of blades (12, 30), the rear edge part being opposite to a front edge part of the each of the plurality of blades in a rotational direction of the each of the plurality of blades, the cutout extending from the rear edge part toward the front edge part such that the cutout divides the rear edge part into an outer rear edge part and an inner rear edge part; characterized by - a first groove part (21, 31) disposed in the outer rear edge part along the outer rear edge part, the first groove part including a plurality of grooves penetrating through the each of the plurality of blades in a thickness direction of the each of the plurality of blades, each of the plurality of grooves extending with a direction of its depth in a direction along a first air flow direction from the rear edge part toward the front edge part, which direction forms a sharp first angle (θ1) with a radial direction of the hub; and - a second groove part (22, 32) disposed in the inner rear edge part along the inner rear edge part, the second groove part including a plurality of grooves penetrating through the each of the plurality of blades in the thickness direction of the each of the plurality of blades, each of the plurality of grooves extending with a direction of its depth in a direction along a second air flow direction from the rear edge part toward the front edge part, which direction forms a sharp second angle (θ2) with the radial direction of the hub, - the plurality of grooves of the first groove part (21, 31) and the plurality of grooves of the second groove part (22, 32) having different shapes when viewed in a rotational axis direction of the hub, the second angle (θ2) being smaller than the first angle (θ1) and the second airflow direction in the inner rear edge part being inclined toward an outer circumference of the hub more greatly compared to the first airflow direction in the outer rear edge part. - a hub; - a plurality of blades (12, 30) arranged in a circumferential direction of the hub; - a cutout in a rear edge part of each of the plurality of blades (12, 30), the rear edge part being opposite to a front edge part of the each of the plurality of blades in a rotational direction of the each of the plurality of blades, the cutout extending from the rear edge part toward the front edge part such that the cutout divides the rear edge part into an outer rear edge part and an inner rear edge part; characterized by - a first groove part (21, 31) disposed in the outer rear edge part along the outer rear edge part, the first groove part including a plurality of grooves penetrating through the each of the plurality of blades in a thickness direction of the each of the plurality of blades, each of the plurality of grooves extending with a direction of its depth in a direction along a first air flow direction from the rear edge part toward the front edge part, which direction forms a sharp first angle (θ1) with a radial direction of the hub; and - a second groove part (22, 32) disposed in the inner rear edge part along the inner rear edge part, the second groove part including a plurality of grooves penetrating through the each of the plurality of blades in the thickness direction of the each of the plurality of blades, each of the plurality of grooves extending with a direction of its depth in a direction along a second air flow direction from the rear edge part toward the front edge part, which direction forms a sharp second angle (θ2) with the radial direction of the hub, - the plurality of grooves of the first groove part (21, 31) and the plurality of grooves of the second groove part (22, 32) having different shapes when viewed in a rotational axis direction of the hub, the second angle (θ2) being smaller than the first angle (θ1) and the second airflow direction in the inner rear edge part being inclined toward an outer circumference of the hub more greatly compared to the first airflow direction in the outer rear edge part.