To provide a method for producing bioethanol capable of mass production and of efficiently reducing the carbon dioxide emission of vehicles, and the like, and free from the problem of food competition.

Bioethanol is produced by hydrolyzing papyrus, recovering produced sugar syrup, adding a yeast to the syrup to ferment the syrup, and concentrating the low-concentration ethanol produced by the fermentation process. Since papyrus has a carbon dioxide absorption of 3-5 times the absorption of wood in the growing stage, the carbon dioxide emission of vehicles, and the like, can be reduced in high efficiency, and the bioethanol can be produced in mass, because the growing period of papyrus is as short as 1 year and the management of the plant in the growing stage is easy. The papyrus is, preferably, crushed in the former stage of the sugar syrup recovery step, and the concentration of the low-concentration ethanol can be carried out, by distilling the ethanol and dehydrating the distillate. Ethanol can be extracted in two stages by solubilizing the residue of the distillation process, recovering the sugar syrup, adding a yeast to the sugar syrup, and concentrating the low-concentration ethanol formed by the fermentation process.