Abstract: Disclosed are plate-shaped fins for a heat exchanger having a coated film formed thereon so that waterdrops can easily fall down from the surface of the plate-shaped fins, the coated film being composed of a solution containing a silicone coating film type resin compound and inorganic finely divided particles. Further, the inorganic finely divided particles are used to provide fine irregular portions on the surface of the coated film formed on the plate-shaped fins so that the area where the waterdrops come into contact with the surface of the fins is reduced.