A hydrogen-developing body of an apparatus for producing hydrogen from an electrolyte solution is disclosed. The hydrogen-developing body is formed from magnesium (Mg) or zinc (Zn) or the like, or an alloy thereof, or has an electrolyte-contacting surface which is formed from magnesium (Mg) or zinc (Zn) or the like, or an alloy thereof. The electrolyte-contacting surface has regions formed from iron (Fe) or a Fe alloy, or the like, which are pellet-shaped and stochastically embedded into the surface such that the Fe/Fe alloy pellets are exposed to the environment of the body.