NOVELTY - Biodiesel fuel oil is manufactured by heating raw material oil under reduced pressure to distill-off volatile component, transesterifying raw material oil and alcohol in the presence of alkali catalyst, separating layers of reaction liquid by gravity separation, in which light liquid layer has fatty acid alkylester and heavy liquid layer has glycerol, removing heavy-liquid layer, removing alcohol in light liquid layer, performing precipitation removal of insoluble content produced in the light liquid by removing alcohol, and contacting light liquid with adsorption agent to adsorb impurities.    USE - Manufacturing method of biodiesel fuel oil (claimed).    ADVANTAGE - Decompression tank is reduced to 1, reverse reaction is prevented, water and alcohol removal performance is high, cost is reduced, apparatus is compact, energy saving, and waste water treatment is unnecessary.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for manufacturing apparatus of biodiesel fuel oil comprising pre-processing and storage tank of raw material oil (1), reaction tank and layer separation tank (7), valve (6) for removing insoluble content in light liquid from the bottom of tank, while moving the heavy liquid before and behind the layer part after reaction out of the system, depressurizing distillation unit of alcohol in light liquid, solid absorbent packed column (8) where light liquid pass through and has an adsorptivity with respect to the impurity in light liquid, removal unit (9) of microparticles and condensate, heating unit (3), evacuation unit (4), stirring unit (5), and evacuation hand combined by depressurizing distillation of volatile component in the heated raw material oil and depressurizing distillation of alcohol in light liquid.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic cross-section of manufacturing apparatus of biodiesel fuel oil.    Pre-processing and storage tank of raw material oil (1)    Catalyst containing alcohol solution storage tank (2)    Heating unit (3)    Evacuation unit (4)    Stirring unit (5)