A method for producing an ornament, in which the ornament has a substrate having a convex front surface and a concave back surface, and an ornamental sheet stacked and bonded on the convex front surface of the substrate, the method for producing an ornament comprising: an ornamental sheet overlaying step for preparing a workpiece having the ornamental sheet positionally aligned and covering the convex front surface of the substrate via an adhesive; a workpiece mounting step for placing a workpiece support base on a workpiece mounting surface formed on a top surface of a suction chamber in a vacuum press bonding apparatus, and placing the workpiece on a workpiece support surface formed on an top surface of the workpiece support base; a pressure sheet pressing step for lowering a pressure chamber relative to the suction chamber, the pressure chamber being disposed directly above the suction chamber in the vacuum press bonding apparatus, and pressing a flexible pressure sheet which defines a bottom surface of the pressure chamber onto the ornamental sheet of the workpiece and the workpiece mounting surface from above; and an ornamental sheet bonding step for increasing a pressure in the pressure chamber to cause the ornamental sheet to be pressed against the convex front surface of the substrate from above by the pressure sheet, reducing a pressure in the suction chamber to evacuate a space between the workpiece mounting surface and the pressure sheet via an air intake hole formed in the workpiece mounting surface, and bonding/fixing the ornamental sheet to the convex front surface of the substrate by the adhesive, wherein the workpiece support base has a flat bottom surface portion capable of firmly bonding to the workpiece mounting surface, the workpiece support surface having a convex shape complementary to the concave back surface of the substrate, and a support-base-side engaging part formed in the workpiece support surface; and the substrate has a substrate-side engaging part capable of mechanically engaging in the support-base-side engaging part, the substrate-side engaging part being formed in the concave back surface of the substrate, and wherein the workpiece is positioned relative to the workpiece support surface in the workpiece mounting step by mechanically engaging the substrate-side engaging part in the support-base-side engaging part; and positional misalignment of the substrate relative to the workpiece support surface is prevented in the pressure sheet pressing step by the mechanical engaging of the support-base-side engaging part and the substrate-side engaging part. an ornamental sheet overlaying step for preparing a workpiece having the ornamental sheet positionally aligned and covering the convex front surface of the substrate via an adhesive; a workpiece mounting step for placing a workpiece support base on a workpiece mounting surface formed on a top surface of a suction chamber in a vacuum press bonding apparatus, and placing the workpiece on a workpiece support surface formed on an top surface of the workpiece support base; a pressure sheet pressing step for lowering a pressure chamber relative to the suction chamber, the pressure chamber being disposed directly above the suction chamber in the vacuum press bonding apparatus, and pressing a flexible pressure sheet which defines a bottom surface of the pressure chamber onto the ornamental sheet of the workpiece and the workpiece mounting surface from above; and an ornamental sheet bonding step for increasing a pressure in the pressure chamber to cause the ornamental sheet to be pressed against the convex front surface of the substrate from above by the pressure sheet, reducing a pressure in the suction chamber to evacuate a space between the workpiece mounting surface and the pressure sheet via an air intake hole formed in the workpiece mounting surface, and bonding/fixing the ornamental sheet to the convex front surface of the substrate by the adhesive, wherein the workpiece support base has a flat bottom surface portion capable of firmly bonding to the workpiece mounting surface, the workpiece support surface having a convex shape complementary to the concave back surface of the substrate, and a support-base-side engaging part formed in the workpiece support surface; and the substrate has a substrate-side engaging part capable of mechanically engaging in the support-base-side engaging part, the substrate-side engaging part being formed in the concave back surface of the substrate, and wherein the workpiece is positioned relative to the workpiece support surface in the workpiece mounting step by mechanically engaging the substrate-side engaging part in the support-base-side engaging part; and positional misalignment of the substrate relative to the workpiece support surface is prevented in the pressure sheet pressing step by the mechanical engaging of the support-base-side engaging part and the substrate-side engaging part.