A serial axial fan includes a first axial fan, a second axial fan, and a rectifying portion. The second axial fan is on one side in the axial direction with respect to the first axial fan and is connected in series to the first axial fan with the rectifying portion interposed therebetween. The rectifying portion includes a chassis with a cylindrical shape surrounding the central axis, a rectifying blade portion extending to a radially inner side from a radially inner surface of the chassis, and an air feeding space on the radially inner side of the rectifying blade portion. The rectifying blade portion extends at least in the axial direction and is inclined relative to another side in the circumferential direction from another side in the axial direction toward the one side in the axial direction.