Abstract: An apparatus is provided for molding an article of footwear having an outer sole, a lateral sole and an inner sole, the outer and lateral soles being of an elastomer, and the inner sole being of a thermoplastic or a mixture of isocyanate and a polyol reacting into polyurethane. The outer sole and the inner sole are each injection molded from an elastomer and bonded at their common contact zone by full vulcanization. The outer sole and the lateral sole may each be of different elastomers. The outer sole and the inner sole are bonded together in the area of their contact zone via chemical bonds between the isocyanate and reactive end-groups of substances added to the elastomer.