An axial flow fan (70) is configured so that a hub (71) and blades (72) which are formed so as to protrude from the outer peripheral edge of the hub (71) are integrally molded from a resin. First blade thin-walled sections (74) are formed in the roots (73) of the blades (72), the roots (73) being those at which the blades (72) are connected to the hub (71), and the first blade thin-walled sections (74) are formed so that radial ribs (75) extending radially toward the outer peripheral side are left.