NOVELTY - The method involves providing several continuous stirred tank reactor combinations and the packed reactor combinations. One of the packed reactor is selected from the packed reactor combinations and the dipped lipase catalyst is filled in the selected packed reactor. The raw oil acid value is measured. The trans-esterification reaction of oil is performed at a temperature of about 20-40 degrees c, by using the enzymatic catalyst, in the presence of (in parts weight) alcohol (1-20) and water (1-10), so as to produce the bio-diesel product.    USE - Method for producing biodiesel used for vehicle such as car and industrial machines.    ADVANTAGE - The trans-esterification reaction of oil can be performed easily, by using the enzymatic catalyst and the biodiesel can be produced efficiently. The production process of the bio-diesel can be simplified. The production cost of the biodiesel can be reduced. The reactivity of the enzymatic catalyst can be increased. The moisture included in the raw material can be collected easily. The need to perform the dehydration process, during the production of biodiesel can be eliminated. The utilization amount of heat source can be reduced. The fuel consumption amount of vehicle can be reduced. The environmental contamination can be prevented. The deacidifying process of biodiesel can be performed easily. The productivity of the biodiesel can be enhanced. The purification process of biodiesel can be simplified.    DETAILED DESCRIPTION - The biodiesel is manufactured using low-class disposable edible oil, brown grease, white grease, yellow grease, dark oil, trap grease, animal oil and animal fat. The conversion ratio of the methyl esters in the first continuous stirred tank reactor is set within the range of 85-90%. The conversion ratio of the methyl esters in the second continuous stirred tank reactor is set within the range of 95-97%. The conversion ratio of the methyl esters in the first packed reactor is set within the range of 98-99%. The conversion ratio of the methyl esters in the second packed reactor is set within the range of 99-95%.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view illustrating the process for producing biodiesel. (Drawing includes non-English language text)