Abstract: An object is to provide a metal complex with high water resistance. The above object is achieved by the metal complex comprising a multivalent carboxylic acid compound, a metal ion belonging to Groups 2 to 13 of the periodic table, an organic ligand capable of multidentate binding to the metal ion, and a monodentate organic ligand capable of binding to the metal ion. The metal complex has excellent gas adsorption, storage, and separation performance as well as excellent water resistance. The metal complex is stably present under high temperature and high humidity conditions, and can maintain high adsorption performance.