In this method for producing an ornament (1), wherein an ornamental sheet (3) is bonded/affixed by means of a vacuum-press-bonding method to the convex front surface (21) of a substrate (2) provided with a convex front surface (21) and a concave back surface (22), a work-support base (6) is placed on a work placement surface (121a) formed on the upper surface of the suction chamber (120) of a vacuum-press-bonding device (100), and the substrate (2) is positioned by fitting an engagement protrusion (28) formed on the back surface of the substrate (2) covered by the ornamental sheet (3) to an engagement hole (68) at the work-support surface (61) formed on the upper surface of the work-support base (6). When bonding/affixing the ornamental sheet (3) to the substrate (2) by means of the vacuum-press-bonding device (100), position deviation of the substrate (2) is prevented by the engagement of the engagement hole (68) and the engagement protrusion (28).