NOVELTY - Animal fat, pure water and sulfuric acid solution are heated, stirred and filtered, to obtain filtrate and oil residue. The oil residue is rinsed using water, rinsing liquid and filtrate are mixed, separated and glycerin solution is distilled. Fresh potatoes are milled, water is added to paste, heated, alpha -amylase, saccharifying enzyme, cellulose, urea and activated yeast liquid are added, fermented and filtered. Animal fatty acid, ethanol and ionic liquid are mixed, stirred, heated, reacted, and separated, to form fatty-acid ethyl ester which is mixed with antioxidant, to obtain biodiesel.    USE - Manufacture of biodiesel from animal fat and fresh potatoes.    ADVANTAGE - The method efficiently, economically and easily provides biodiesel from animal fat and fresh potatoes.    DETAILED DESCRIPTION - Animal fat (in parts weight) (100) is crushed to mud state, pure water (15-25) and sulfuric acid solution (25-35) are added to the mixture, heated at 90-100 degrees C, stirred for 1-2 hours, and heated mixture is filtered, to obtain filtrate and oil residue. The oil residue is rinsed using water, rinsing liquid and filtrate are mixed, the filtrate is maintained for 8 hours, the liquid is transferred to a liquid-dispersion hopper in which upper layer is animal fatty acid and lower layer is sulfuric acid-glycerin solution. The glycerin solution is distilled at 90-100 degrees C. Fresh potatoes (1010) are milled, water (30-50) is added to the paste material, heated to 70-80 degrees C, alpha -amylase of the fresh potato is added, liquefied for 30 minutes, cooled to 30-35 degrees C, saccharifying enzyme, cellulose, urea, and activated yeast liquid are added to the cooled liquid at 30-35 degrees C, fermented for 6 days, filtered, and distilled. Animal fatty acid (1 part mole), ethanol (1-4 parts mole) and ion liquid (0.2-0.6 part mole) are mixed, stirred, heated to 70-80 degrees C, reacted for 4-6 hours, upper layer of fatty acid ethyl ester is separated with the liquid-dispersion hopper, and ion liquid lower layer is recycled and reutilized, to form fatty-acid ethyl ester. Subsequently, antioxidant is added to the fatty acid ethyl ester, to obtain biodiesel. The ionic liquid is 1-ethyl-3-dimethylimidazolium tetrafluoroborate ionic liquid or N-methyl-2-pyrrolidone methanesulfonic acid ionic liquid.