A concave half (10) having a conical inside and a convex half (20) having a conical outside and being fitted therein are fitted in each other. An openable and closable, loop-shaped supporting means as a toggle-jointed link (30) rotatably supports and pushes a cylindrical part (23) of the convex half (20) onto the axis on at least three points on the outer periphery of the cylindrical part (23), with an axis of the concave half (10) and an axis of the convex half (20) being aligned with each other when the supporting means is closed. The toggle-jointed link (30) is openable and closable, wherein a plurality of rolling objects such as rollers (31) are provided inside the loop, thereby improving function as a bearing of the supporting means and efficiently manufacturing quality rolled cones (40).