Abstract: A metal-organic framework (MOF) having the function of controlling the release of guests is provided in which reversible release control is possible and release control can be rapidly performed and which is capable of accommodating the release of various guest molecules. The metal-organic framework comprises both an organic ligand having two or more functional groups (coordinating functional groups) capable of coordinating to a metal atom and metal ions that combine with the coordinating functional groups of the organic ligand, and has a structure in which one metal ion has combined with two or more of the coordinating functional groups to connect multiple molecules of the organic ligand. The metal-organic framework/Stimulus-responsive polymer composite was obtained by affixing a stimulus-responsive polymer to at least some of the surface of the metal-organic framework. The stimulus-responsive polymer may be affixed by bonding to the organic ligand.