To microbiologically produce a large amount of hydrogen.

Hydrogen is produced by leaving to stand one or more species of bean-curd refuse, rice bran or wheat bran or a food-associated waste containing those inoculated with or without hydrogen-producing bacteria in a wet condition and culturing inoculated hydrogen-producing bacteria and/or hydrogen-producing bacteria included in the food associated waste. A large amount of hydrogen is produced by using the bean-curd refuse, the rice bran or the wheat bran.