To provide a molding light in weight and excellent in regidity without bursting appearance, by having a rid structure in the molding, and forming a hollow part in the molding, in the molding for a wheel cover for a vehicle.

A denatured polyphenyline ether resin is used, for instance, mean thickness of a molding is formed in 1.5mm, and a vehicle wheel cover, having a rib structure of ten radial with lib width 6.0mm with a height 6.0mm from product surface of a rib, is formed by gas hollow molding. A hollow part 3 is formed in the vicinity of a root in a rib structure part. In the gas hollow molding, at 270°C of cylinder temperature, under a condition of 50°C of metal mold temperature, simultaneously with ending injection of the resin, nitrogen gas is injected under a 200kgf/cm2 pressure. The rib structure 1 may be formed as a structure radially toward a peripheral part from the molding center part and adding a circular rib.