A machine was named Impact-Cell-Mill (ICM) which has been developed for the dedestruction of single cell microbe such as yeast and chlorella. We have been come to many difficult problems in the nozzle, disk, valve, pressure sealing materials and mechanical technique, etc. Teflon gave good results as the materials for sealing the machine and four or more sheets of seal packing were necessary for durability of plungers which made high pressure as 600-800 kg/cm2. Sintered hard alloy was suitable as the materials of a nozzle, disks, valves. In respect of the angle of the nozzle, 15 degrees was superior to 55 degrees. The nozzle with a polished surface showed good results. Baker’s yeast could be crushed about 33-44s passing once through ICM under the condition of 600-800 kg/cm2 as spouting pressure. The crushing energy at that time about 24-26 Cal/g.