PURPOSE: To crush in a short time and to surely prevent over-crushing by forming the structure of crushing a raw material with its centrifugal fluidizing or improving the surface quality and discharging quickly the fine powder caused by the leading-in of a gaseous body into the device.

CONSTITUTION: Raw material and crushing medium or quality improving medium are stored in the chamber 23 surrounded by the dish face 2A of a dishpan 2 and the inner wall face 1A of a fixed ring 1 and by rotating the dishpan 2, the raw material and medium perform the circular movement in the vertical direction circularting the dish face 2A and inner wall face 1A as well with revolving in the circumferential direction at the speed slower than the rotating speed of the dishpan 2. A spiral proceeding movement like making a rope combined with these two movements in performed. Accordingly, the mutual raw material or raw material and medium are rubbed each other, the raw material is crushed and a child substance is peeled off from the surface of the granular body to be processed. In this case, the electric power consumption rate for driving the dishpan 2 by its rotation is remarkably reduced by taking the weight ratio A/B of the weight A of the medium to the weight B of raw material at 0.5-2.