Abstract: The present invention relates to a technique for delivering gases into the human body or generating gases inside the human body, such as a method for encapsulating gases and a gas storage vessel. The present invention relates to a gas storage capsule and to a method for producing the gas storage capsule, wherein the capsule is dissolved in water such that the air-tightness thereof is gradually degraded and the gas contained in the capsule can be gradually leaked to the outside of the capsule. The present invention also relates to a hydrogen-generating material which directly generates hydrogen gases in vivo, and to a hydrogen-generating candy for directly encapsulating hydrogen using the material and delivering the thus-encapsulated hydrogen into the intestines, as well as to a method for producing the candy.