Abstract: A method for producing second-generation bioethanol with a reduced production cost. The method for producing bioethanol, which is a method for producing bioethanol from cellulose, includes: in order, a saccharification step of adding an enzyme to the cellulose for saccharification to obtain a sugar liquid; a step of obtaining a concentrated sugar liquid by concentrating the obtained sugar liquid; a fermentation step of adding yeast to the concentrated sugar liquid for fermentation to obtain hydrous bioethanol; and a concentration step of concentrating the hydrous bioethanol to obtain bioethanol. The method further includes at least one of a step of collecting the enzyme using a ceramic membrane after the saccharification step and a step of collecting unreacted yeast using a ceramic membrane after the fermentation step, and/or in the step of obtaining the concentrated sugar liquid, the sugar liquid is concentrated using a protein-supported polyamide RO membrane.