PURPOSE: To optimally control cooling condition and to improve the quality by providing a measure in a manifold corresponding to a pointer integrated with a handle in a flow rate adjusting cock arranged in a nozzle.

CONSTITUTION: A steel belt 3 is extended over the outer periphery of a ring mold 1, and the manifold 6 having many nozzles 7 along the outer periphery of the ring mold 1 is arranged. Cooling water from the nozzles 7 is spouted toward the outer periphery of the ring mold 6. Then the flow rate adjusting cock 9 is arranged in the nozzle 7. The measure 12 corresponding to the pointer 11 integrated with the handle 10 in the cock 9 is arranged on the plate-like member 13 fixed to the manifold 6. Thus, the cooling water spouting quantity of the nozzle 7 can quantitatively be adjusted.