In the rolling mill, an orifice (20) (contracted flow part) and a chamber (21) (expanded part) are provided in a hydraulic line (19) for a hydraulic cylinder (17) (hydraulic pressing means). The orifice (20) is disposed more to the hydraulic cylinder (17) side than the chamber (21). The internal diameter of the orifice (20) is set to be 2.5 mm (Õ) or greater and 15 - 85% of the internal diameter of the hydraulic line (19). Thus, it is possible to control milling vibration.