PURPOSE: To simply and efficiently obtain an alcohol as a chemical raw material, etc., in a high yield by treating starch-containing fine algae under a specific condition, saccharifying and alcohol-fermenting the treated fine algae, and subsequently subjecting the fermented product to physical treatments such as an ultrasonic wave treatment and to a reaction under a high humidity and a high pressure.

CONSTITUTION: This method for producing an alcohol from fine algae as a raw material comprises treating the starch-containing fine algae with one or more kinds of solvents, saccharifying the starch in the algae with a saccharifying enzyme, and subsequently subjecting the saccharification product to an alcohol fermentation treatment. The solvents are selected from alcoholic, ketonic, halogenated hydrocarbon and ethereal organic solvents which have a fine alga cellular membrane-denaturing action and a fine alga starch-depositing and saccharifying action.