PURPOSE: To preserve stably microorganisms for a long period of time without deterioration by forming a tablet consisting essentially of a mixture composed of microorganisms such as bacteria, euglena, etc. and water soluble polysaccharides such as trehalose, cane sugar, etc.

CONSTITUTION: 1 Or ≥2 kinds among water soluble polysaccharides including disaccharides such as trehalose, cane sugar, gentiobiose, cellobiose, malt sugar, lactic acid, etc., polysaccharides such as starch, glycogen, etc. are mixed and are softened by heating, then the mixture is kneaded. Powders of microorganisms including Sarcodina such as bacteria, ameba, etc., Flagellata such as euglena, etc. and Flagellata such as Paramecium, etc. are added to the kneaded matter and the mixture is further kneaded. The final kneaded matter is molded to a tablet of an optional shape such as spherical, circular cylindrical or other shapes and an optional size. The amt. of the microorganisms to be added into the water soluble polysaccharides is usually 0.01W10wt%.