NOVELTY - A polymer complex regularly arranged so that substituent (A) may face inner surface of specific pore group (B1) among 2 or more types of pore groups, is prepared. The molecule of electrolyte solution is included by contacting the electrolyte solution with the polymer complex in the pores of pore group (B1) of the polymer complex. The polymer complex consists of a non-coordinating aromatic compound including an aromatic compound as a ligand having two or more coordinating sites, a metal ion as a center metal, and a non-coordinating aromatic compound.    USE - Method of holding electrolyte solution used in secondary batteries e.g. lithium secondary batteries of notebook personal computers and mobile telephones.    ADVANTAGE - The method enables easy inclusion of electrolyte solution in the pores, without impairing the three-dimensional lattice of the polymer complex. Volatilization of electrolyte solution is suppressed. The electrolyte solution can be held over a long period of time.    DETAILED DESCRIPTION - A polymer complex regularly arranged so that substituent (A) may face inner surface of specific pore group (B1) among 2 or more types of pore groups, is prepared. The molecule of electrolyte solution is included by contacting the electrolyte solution with the polymer complex in the pores of pore group (B1) of the polymer complex. The polymer complex consists of a non-coordinating aromatic compound including an aromatic compound as a ligand having two or more coordinating sites, a metal ion as a center metal, and a non-coordinating aromatic compound. The polymer complex has a three-dimensional lattice including a stacked structure formed by the non-coordinating aromatic compound being inserted between the aromatic compound ligands into the three-dimensional network structure formed by coordination of the aromatic compound ligand and the center metal ion. In the three-dimensional lattice, 2 or more types of pore groups which consist of mutually same pores having intrinsic affinity with respect to a guest component are provided. The non-coordinating aromatic compound has specific substituent (A) in the specific position on a self aromatic ring. An INDEPENDENT CLAIM is included for electrolyte solution holding component comprising the polymer complex.