[Problem] To provide a selective hydrogenation apparatus with which a hydrogen-containing biologically applicable liquid can be obtained without changing the properties of a biologically applicable liquid.[Solution] A hydrogen-generating system comprising a hydrogen-generating agent as an essential component is accommodated in a hydrogen bubble-forming unit that has a gas-liquid separation section containing a gas permeable membrane or an openable valve, and hydrogen gas generated in the hydrogen bubble-forming unit by reacting the hydrogen-generating system and water for generation in the hydrogen bubble-forming unit is fed to a biologically applicable liquid through the gas-liquid separation section, whereby a hydrogen-containing biologically applicable liquid is obtained.