The present application provides a radiation damage protecting agent comprising hydrogen gas as an active ingredient at a concentration of 18.5% by volume or less, for treating or alleviating, in a hyperbaric capsule under a pressure higher than standard atmospheric pressure, radiation damage in a human patient who has been exposed to radiation or who has received or receives radiotherapy, and a hyperbaric capsule for administering a hydrogen gas-containing therapeutic agent such as the radiation damage protecting agent to a patient including a human.

An eye mask-type hydrogen supply device that is freely portable when carried by a user and with which it is possible to supply hydrogen to the areas around both eyes and the eyeballs while warming the eyelids, wherein the eye mask-type hydrogen supply device can be used continuously by replacing a hydrogen gas supply pack.

A hydrogen generation device includes a tubular tank and a top lid combined with the tank. An immersion tube in which a hydrogen generating agent package is stuffed is placed in the tank. The hydrogen generating agent package is submerged in water after water is poured in the tank to generate hydrogen, which is released through a tank opening of the tank. The hydrogen generating agent package accommodates hydrogen generating agent powders including calcium oxide and aluminum powders, both of which are mixed and wrapped with a nonwoven fabric, as well as a little catalytic sodium carbonate added inside. For inhibition of free radicals and promotion of metabolism, the hydrogen generation device is further provided with a connector and a hose for a skin-care instrument, a nasal mask, an eye shield or an ear cleaner through which hydrogen is supplied as required.