PURPOSE: To obtain an agitator mill having a separating means which exhibits a good fluid pressure packing property and wear resistance and is freely rotatable by allowing milled material to flow toward an outlet via the separating means and rotating the separating means by fluid coupling of an agitator shaft and the separating means.

CONSTITUTION: The agitator mill 10 is provided with a housing 12 which has an inlet 17 for introducing the material to be milled toward a milling chamber 14 and the outlet 19 for discharging the milled material, the agitator shaft 20 which has a first end 24 freely rotatably supported to the first end 16 of the milling chamber 14 and a second end 18 of a free end and has a plurality of spatially arranged agitator disks 22 and a separator screen device 40 which is freely rotatably supported at the second end 18 of the housing 12 and has a front end extending near to the second end 26 of the agitator shaft 20. The milled material flows into the outlet 19 through the screen device 40 and the screen device 40 is rotated by the fluid coupling of the agitator shaft 20 and the screen device 40.