The invention relates to novel foamed nickel with a hierarchical pore structure and a manufacturing method and application of the novel foamed nickel. Unlike existing foamed nickel, the foamed nickel has a well-developed hierarchical pore structure including pores having a size of 4 [mu] m or less in addition to macropores having a size of 100 [mu] m to 900 [mu] m, and thus can have a significantly large specific surface area. Therefore, the device can be variously applied to electrochemical reactions of a water electrolysis system, an exhaust gas purification filter and the like.
