To provide a labor-saving device for surely and rapidly grinding and dispersing very fine particles in a liquid phase.

Between an internal shaft 7 and an external case 1, a plurality of rollers 3b are arranged. Partition plates 3a and 3c are placed between the adjoining rollers 3b, slidably in the axis direction of the internal shaft 7 and the external case 1 and in order that an alternating route 10 which flows alternately to the side of the internal shaft 7 and that of the external case 1 may be formed. The very fine particles in the liquid phase are ground by squeezing pressure generated between the rollers 3b and the partition plates 3a and 3 c by rotating the internal shaft 7 or the external case 1 and by running the liquid phase containing the very fine particles in the external case 1.