PURPOSE: To restrain separation of air to reduce noises by covering the surface of a fan body constituted with glass fiber mixed reinforced plastic mold by means of an extremely thin film which forms the surface smoothly.

CONSTITUTION: Each part of a fan body 1 is made of acrylonitrile styrene-resin containing a large number of glass fibers and an extremely thin film 6 in which antibacterial agent is mixed in acrylonitrile-butadiene-styrene resin is spread on the surface of the fan body. A transfer film 7 is formed by fixing a film 6 to be transferred to a mold on one side of a carrier film 8, and arranging the transfer film 7 at required positions in the mold 10 of a fan assembly 3, an then, injecting and molding the resin in the mold, thereby the film 6 is separated from the carrier film 8 due to pressure, heat, etc., so that the transfer is carried out on the required portions of the fan assembly 3. The surface of each part with regard to an air flow is formed by the film 6 in a smooth surface having no unevenness caused by the glass fibers 1a.