A cross-flow fan is configured so that the strength of the cross-flow fan is increased while an increase in flow pass loss caused by the reinforcement member, such as a support plate, of the cross-flow fan is minimized. Blades (40) extend in the longitudinal direction from a support plate (50). An auxiliary ring (60) is located at the intermediate portions of the blades (40) in the longitudinal direction and is joined to the outer ends (40a) of the blades (40). The auxiliary ring (60) is located at a position away from support plate-side blade base sections (40c) of the blades (40) by a distance of 55% or more of the distance from the base sections (40c) of the blades (40) to the tip sections (40d) thereof.
