PURPOSE: To provide a lightweight, high-rigidity fan by arranging a lightweight core material in the cavity of dies, arranging a shaft core material on a fitting shaft section, surrounding the whole faces of a blade body section and the fitting shaft section with a reinforcing material, then injecting plastic.

CONSTITUTION: A lightweight core material 5 is arranged on a fan blade body section 1 in the cavity C of fan molding dies A, B via a long fiber-shaped reinforcing material 4, a shaft core material is arranged on a fitting shaft section 2, and the whole faces of the blade body section 1 and the fitting shaft section 2 are surrounded with the long fiber-shaped reinforcing material 4. Thermosetting plastic is injected and integrally hardened, thus a lightweight, high-rigidity FRP-fan is obtained.