NOVELTY - A material is added to a reactor containing a catalyst (3). The methanol (1) is refluxed, and esterified. The methanol is evaporated, and the water generated by the reaction is removed. The distilled material is transferred into an outflow opening of a dehydrating tower. When the distilling temperature is 67 degrees C or more, distilled methanol with purity of 95% or less is transferred to a methanol dehydrating tower (7). The methanol with purity of 99% is obtained at the top of the tower, and residual alcohol at the bottom of the tower is evaporated in nitrogen atmosphere.    USE - Esterification of methanol used for producing biodiesel.    ADVANTAGE - The method enables esterification of methanol with high conversion rate.    DETAILED DESCRIPTION - A material is added to a reactor containing a catalyst. The content of catalyst is 2 mass% with respect to oil material (2). The mol ratio of methanol and oil material is 2-3:10. The temperature of an esterifying reaction kettle (4) is 60-70 degrees C. The methanol is refluxed, and esterified for 1-2 hour. The methanol is evaporated, and the water generated by the reaction is removed from the esterifying reaction kettle. The distilled material is transferred into an outflow opening of a dehydrating tower. The purity of distilled methanol is 96-99%. The concentration of distilled methanol is reduced with respect to the methanol concentration in the liquid phase, and the distilling temperature of gas phase is improved. When the distilling temperature is 67 degrees C or more, distilled methanol with purity of 95% or less is transferred to a methanol dehydrating tower. After the methanol and water in the esterifying reaction kettle are distilled completely, the excess methanol in a methanol recycling tank is added to the esterifying reaction kettle, and the esterification and dehydration are repeated for 3 times such the esterifying conversion percent reaches predetermined value. When the tower kettle liquid level of the methanol dehydrating tower reached to 2/3, the feeding material is stopped and methanol containing water is removed. The methanol with purity of 99% is obtained at the top of the tower, and residual alcohol at the bottom of the tower is evaporated in nitrogen atmosphere. The content of the residual alcohol in water is reduced to 10 ppb or less, and is discharged out of the tower and the methanol containing water is recycled.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of the apparatus for esterification of methanol.    Methanol (1)    Oil material (2)    Catalyst (3)    Esterifying reaction kettle (4)    Methanol dehydrating tower (7)