Provided are a hydrogen/oxygen generation system and a hydrogen/oxygen generation method, with which an increase in size due to the addition of a circulation apparatus and a centrifugation apparatus for supplied water can be mitigated, and instability of supply of water can be reduced. The hydrogen/oxygen generation system 10 is characterized by including: an electrolytic cell 20 for generating hydrogen and oxygen by means of electrolysis of water supplied thereto and discharging the generated hydrogen and oxygen as separate generated gases; an accumulator 30 in which a water accumulation chamber 33 for accumulating water and a gas chamber 34 to which a pressure-accumulation gas is supplied are disposed separated by an elastic body film 32, and which transfers the water accumulated in the water accumulation chamber 33 to the electrolytic cell 20 using a transfer pressure corresponding to the pressure of the accumulation gas in the gas chamber 34; a water supply section 40 for supplying the water to the water accumulation chamber 33; and a gas supply section 50 for supplying the pressure-accumulation gas to the gas chamber 34.