Abstract: An easy-to handle hydrogen generating agent has been invented in which a hydrogen compound such as alkali metal hydrides, alkali earth metal hydrides and metal borohydride salts is embedded in a water-soluble solid compound such as a polyethylene glycol and organic acid. The hydrogen generating agent dissolves in water to slowly generate hydrogen gas. The oxidation-reduction potential of the water that has dissolved the hydrogen generating agent is shifted to the reducing side remarkably; therefore, the hydrogen generating agent can be used for preparation of cosmetics, beverage and bath water having reducibility. Also, the generated hydrogen can be used as a fuel for a fuel cell.