A resilient surface sheet element 14 is vacuum molded from a resilient laminate sheet member 13 including a skin sheet 10 and a foam sheet 12. The resilient surface sheet element 14 is placed in a predetermined recess 16 of a female mold 15 for molding an instrument panel. After a first thermoplastic resin 18 is fed into a space between a male mold 17 and the resilient surface sheet element 14 placed in the female mold 15, the female mold 15 and the male mold 17 are closed tightly. The first thermoplastic resin 18 then flows through a first cavity section formed on a rear face of the resilient surface sheet element 14 to be integrated with the resilient surface sheet element 14. Before the first plastic resin 18 completely hardens in the first cavity section, a second thermoplastic resin 21 is injected from an injection gate 20 into a second cavity section adjacent to the first cavity section to securely fuse and join with the first thermoplastic resin 18.