A method of adding hydrogen to a fluid that is applicable to living organisms via inhalation, drinking or injection, the method comprising use of a selective hydrogen adding equipment that comprises: a hydrogen generating system that contains a hydrogen generating agent as an essential constituent, the hydrogen generating agent being hydrogenated metal or metal having higher ionization tendency than hydrogen; a hydrogen bubble forming implement (c-3; d-3) that stores the hydrogen generating system for generating hydrogen gas by a reaction between the hydrogen generating system and water that is provided for the purpose of generating hydrogen, the hydrogen bubble forming implement having a gas/liquid separating section (a, b) including an open-close type valve (a), and a closed container (e) for storing the fluid, characterized by the steps of: a) providing water for the purpose of generating hydrogen to the hydrogen generating system, b) disposing the hydrogen bubble forming implement in the closed container, and c) supplying the hydrogen gas into the closed container storing the fluid via the gas/liquid separating section thereby to provide a hydrogen-containing fluid to be applied to the living organisms, wherein the open-close type valve is opened by a gas pressure of the hydrogen gas generated inside of the hydrogen bubble forming implement owing to a reaction between the hydrogen generating system and the water provided in step (a), thereby to exhaust hydrogen gas into the closed container outside of the hydrogen bubble forming implement, the open-close type valve being closed after the exhaust, thereby to isolate the hydrogen generating system from the fluid to be applied to the living organisms. a hydrogen generating system that contains a hydrogen generating agent as an essential constituent, the hydrogen generating agent being hydrogenated metal or metal having higher ionization tendency than hydrogen; a hydrogen bubble forming implement (c-3; d-3) that stores the hydrogen generating system for generating hydrogen gas by a reaction between the hydrogen generating system and water that is provided for the purpose of generating hydrogen, the hydrogen bubble forming implement having a gas/liquid separating section (a, b) including an open-close type valve (a), and a closed container (e) for storing the fluid, characterized by the steps of: a) providing water for the purpose of generating hydrogen to the hydrogen generating system, b) disposing the hydrogen bubble forming implement in the closed container, and c) supplying the hydrogen gas into the closed container storing the fluid via the gas/liquid separating section thereby to provide a hydrogen-containing fluid to be applied to the living organisms, a) providing water for the purpose of generating hydrogen to the hydrogen generating system, b) disposing the hydrogen bubble forming implement in the closed container, and c) supplying the hydrogen gas into the closed container storing the fluid via the gas/liquid separating section thereby to provide a hydrogen-containing fluid to be applied to the living organisms, wherein the open-close type valve is opened by a gas pressure of the hydrogen gas generated inside of the hydrogen bubble forming implement owing to a reaction between the hydrogen generating system and the water provided in step (a), thereby to exhaust hydrogen gas into the closed container outside of the hydrogen bubble forming implement, the open-close type valve being closed after the exhaust, thereby to isolate the hydrogen generating system from the fluid to be applied to the living organisms.