PURPOSE: To simultaneously perform two processes to cover a core metal with expandable resin and with outer leather by a method wherein the expandable resin is poured in the interior of a ring-like leather tubular body covering the whole ring part of the core metal so as to reaction-mold the resin therein.

CONSTITUTION: A cavity 8, which corresponds to the finished shape of a steering wheel main body 1, is provided in a molding die 7. A core metal 2 is fairly and correctly set to the cavity by utilizing a steering wheel shaft connecting part 2c. Vent holes 13 are provided at the upper and lower ends of the molding die 7. Vent holes 14 are also provided at the upper and lower ends of a leather tubular body 4. In addition, gates 10 and the vent holes 13 and 14 are arranged on the back side of the steering wheel main body so as to prevent gate marks and vent marks from developing on the front side of the steering wheel main body. Thus, expandable resin is poured through the gates 10 and the air is exhausted through the vent holes 13 and 14 so as to fill the interior of the leather tubular body 4 in order to perform the reaction molding of a steering wheel.