NOVELTY - Organic waste treating agent comprises organic raw material(s) (OM) chosen from chaff, wooden, septa and bamboo fragments as main body. OM is impregnated with hardness improver, heated under non-oxidizing atmosphere to mix organic substance (OS) and inorganic substance (IS), and used as porous composite piece. OS controls moisture content, and IS controls strength and preservation characteristics.    USE - For decomposing-treating organic waste.    ADVANTAGE - The porous composite piece excels in wear resistance, corrosion resistance and is resistant to degradation by organic waste decomposing microbe, hence can be effectively used for long time. The composite piece also accelerates proliferation of organic waste decomposing microbes. The formation of pores on organic material increases surface area and improves support characteristics, thereby organic waste treating agent used per unit weight of organic waste is reduced. Since the organic substance in treating agent controls moisture, water generation by organic waste and bad odor due to changing of microbes into anaerobic bacteria are prevented. the removal of sap from organic raw material accelerates propagation of microbe.    DETAILED DESCRIPTION - Organic waste treating agent comprises support and/or breeding medium for microorganism capable of decomposing organic waste. The agent contains organic raw material(s) chosen from wooden fragment, septa fragment, bamboo fragment and chaff as main body. Organic raw material is impregnated with hardness improver, hardness of organic raw material is improved by intermingling organic and inorganic substance by heating under non-oxidizing atmosphere, and used as porous composite. Organic substance controls moisture content, and inorganic substance controls strength and preservation characteristics. An INDEPENDENT CLAIM is also included for manufacture of organic waste treating agent. Water soluble sap component is removed from organic raw material, and the organic raw material is impregnated with a material which improves hardness by heating. The impregnated material is heated under non-oxidizing atmosphere to obtain composite piece. The humidity of composite piece is controlled by immersing in natural water, and the composite piece is subsequently acid treated. The pH of acid treated composite piece is regulated. The composite piece is immersed in aqueous enzyme solution which activates microorganisms capable of decomposing organic waste, and organic waste treating agent is manufactured.    DESCRIPTION OF DRAWING(S) - The figure shows the flowchart of organic waste treating agent manufacture. (Drawing includes non-English language text).