PROBLEM TO BE SOLVED: To provide an oxygen reduction apparatus that is made not to generate hydrogen, in an oxygen reduction apparatus utilizing a solid polymer electrolyte membrane.SOLUTION: Provided is an oxygen reduction apparatus 200 utilizing a solid polymer electrolyte membrane process and in which a voltage is applied while maintaining a constant-current control until the potential difference between an anode 208 and a cathode 210 reaches an upper limit potential difference and upon reaching the upper limit potential difference a constant voltage control is carried out so as not to exceed the upper limit potential difference.【課題】固体高分子電解質膜を用いた減酸素装置において、水素が発生しないようにした減酸素装置を提供する。【解決手段】固体高分子電解質膜方法を用いた減酸素装置２００において、アノード２０８とカソード２１０との間の電位差が、上限電位差に到達するまでは定電流制御を維持しつつ電圧を印加し、上限電位差に到達するとこの上限電位差を超えないように定電圧制御する。【選択図】 図９
