<;P>;PROBLEM TO BE SOLVED: To provide a method for producing a health food, a feed and a fertilizer by a fermentation treatment with which a crustaceans, eggshell, seafood processing residue, soybean cake, soybean curd refuse etc., hard to ferment can be effectively utilized. <;P>;SOLUTION: Enteric bacteria collected from digestive tracts of water- or seawater-fish and shellfish are cultured in a bacterial bed of dried soybean curd refuse and rice bran, the culture product is mixed with a new bacterial bed and an existing environmental bacterium to make a combined bacterium to be used. A fermentation object is used as a first raw material, a material such as dried soybean curd refuse, defatted soybean cake, rice bran etc., satisfying a production purpose is selected as a second raw material, the raw materials are mixed with stirring and a combined fermentative bacterial group is planted on the mixture. The mixture is fermented with stirring by a heat-retaining batch-type fermentation machine (fermentation tank 1) from a low temperature until the temperature reaches 75-85°;C. <;P>;COPYRIGHT: (C)2010,JPO&INPIT