To reinforce the strength of a cross-flow fan while controlling an increase in flow path loss caused by a reinforcement member of the cross-flow fan such as a support plate. Plural blades (40) extend in a lengthwise direction from a support plate (50). An auxiliary ring (60) is positioned on a lengthwise direction intermediate section of the plural blades (40) and is combined with outer ends (40a) of the plural blades (40). The auxiliary ring (60) is located in a position away from blade base portions (40c) on the support plate side of the blades (40) by a distance equal to or greater than 55% of the long dimension from the blade base portions (40c) to blade distal end portions (40d).
