An oxygen reduction catalyst and the catalyst as an electrode catalyst are provided. The oxygen reduction catalyst is characterized by including an organometallic polymer structure in which a transition metal or zinc is coordinated with an organic polymer compound including a ligand comprising a heterocyclic 5-membered ring or a heterocyclic 6-membered ring containing at least not less than two elements selected from nitrogen (N), oxygen (O), sulfur (S), and selenium (Se), and derivatives thereof. Thereby, even when an amount of a metal is smaller than that in a platinum particulate catalyst, an oxygen reduction capacity equal to or more than that of the platinum particulate catalyst can be obtained. Further, by coordinating a metal with an organic polymer, stability in an oxygen reduction condition can be significantly improved compared to the case of metal based macrocyclic compounds.