PURPOSE: To make attachment of a first and second skin materials easy and to improve appearance by attaching the ringlike patching material to an upper mold and a lower mold respectively so as to wrap the terminals of the first and second skin materials and introducing foaming synthetic resin raw liquid into the lower mold in a mold matching state.

CONSTITUTION: Both a first skin material 18 and a second skin material 19 are provided to the molding faces 15, 16 of a lower mold 12 and an upper mold 13 respectively. Patching materials 21, 22 formed into a ring shape are attached to both the terminal 18a of the first skin material 18 provided to the lower mold 12 and the terminal 19a of the second skin material 19 provided to the upper mold 13 respectively. The outside face of the patching material 21 is attached to a ringlike groove 12a provided to the outer peripheral edge of the molded face 15 of the lower mold 12. Then padding material 29 is formed by foaming and curing of foaming resin raw liquid and a molded body wherein the padding material and the skin material have been integrated into one body is obtained.