PURPOSE: To decrease the energy required for a treatment by providing vibrating vanes on a vibrating shaft and forming the vibrating vanes by a pair of opposed vanes.

CONSTITUTION: Liquid, such as scum 10 or foamed liquid 11, existing in the opposed space 7 of the opposed vanes 2A, 2B receives pressing force upon descending of the vibrating vanes 2 when the vibrating vanes 2 vibrate vertically. This pressing force is condensed and intensified by the opposed vanes 2A, 2B converging upward and the impulsive component of force of fluidization in the direction of vane tips 4 is simultaneously generated by the opposed vanes 2A, 2B inclining and expanding toward the vane tips 4. The impulsive flow toward the vane tips 4 is generated at every operation of the vibrating vanes 2, by which the liquid is strongly ejected and fluidized outward from the vane tips 4. The treating function is well and stably maintained in this way.