Radiating fin and radiating method using the radiating fin

It is an object of the present invention to provide an inexpensive heat radiating fin having a high cooling effect. A coating metal layer consisting of a metallic material with an ionization tendency larger than that of silver is coated on a surface of a heat radiating fin main body by plating or the like to form the heat radiating fin. Thus, the coating metal layer has a layer thickness which increases a difference between a heat capacity of the coating metal layer and a heat capacity of the air, and facilitates chemical adsorption of molecules in the air. The heat radiating fin radiates heat while being brought into contact with the air serving as a cooling fluid.