PURPOSE: To decrease intrinsic vibration in low speed revolution at an initial revolution, and resonant vibration at a time of middle speed revolution by a method wherein an annular ring which is concentric with a cylindrical container is provided movably in the horizontal direction substantially in the central part in the vertail direction inside of an annular fluid balancer with liquid sealed in an outer periphery of the cylindrical container.

CONSTITUTION: In a process of making juice, at a time of low speed revolution at an initial revolution of a centrifugal separating basket 10 when juice is not yet produced, cut material is not put into the centrifugal separating basket 10, and intrinsic vibration of a juicer occurs. In the middle speed revolution, resonant vibration occurs. To loosen these vibrations, it is most preferable that a position of liquid 16 of a fluid balancer 12 provided in the centrifugal separating basket 10 is low. The liquid 16 of the fluid balancer 12 is apt to rise up by the vibration of the initial revolution and the revolution of the centrifugal separating basket 10. In this instance, an existence of an annular ring 15 positioned substantially in the central part of the fluid balancer 12 prevents the liquid 16 from rising up, whereby the vibrations are reduced.