A plurality of carbon fibers having a surface having a metal-plated layer (Cu-plated layer) are stood vertically on a flat plate-like provisional substrate by electrostatic flocking, and one end of the carbon fibers is provisionally adhered to the provisional substrate with an adhesive. The other end of the carbon fibers which is not provisionally adhered is contacted with a substrate (Cu plate) having a surface coated with a solder paste and, in this state, a brazing material (solder) is melted and cooled, and carbon fibers and a substrate are brazed (soldered). After completion of mechanical and thermal connection between the substrate and the carbon fibers, this is immersed in an organic solvent, and the provisionally adhered provisional substrate is peeled from the carbon fibers to manufacture a radiating fin.