To provide nitrogen-containing aromatic compounds with excellent oxygen reduction activity, metal complexes containing them, and catalysts and electrodes employing the same, the present invention provides an aromatic compound satisfying the following conditions (a) and (b): (a) It has 2 or more structures surrounded by at least 4 coordinatable nitrogen atoms (which structures may be the same or different), (b) At least one of the nitrogen atoms composing the structure is a nitrogen atom in a 6-membered nitrogen-containing heterocyclic ring.