The method for producing hydrogen is characterized by comprising bringing an anaerobically fermented liquid at or below pH 5.5 into contact with acting electrodes at -0.35V(silver-silver chloride electrodes potential reference) or more basely polarized ones that carry microorganisms. 微生物を担持する−0.35V(銀塩化銀電極電位基準)又はこれより卑に分極された作用電極に、pH5.5以下の嫌気性発酵液を接触させることを特徴とする水素製造方法。 - 特許庁