The creation of supramolecular structures through the self-assembly of cyclodextrin (CD) molecules enhances the molecular recognition ability of CDs and enables functions that cannot be achieved by individual CD molecules alone. CDs are known to regularly assemble intermolecularly through hydrogen bonding between hydroxyl groups on the upper and lower rims of their rings or through host-guest interactions with guest molecules, forming cage-type, channel-type, and layered assembly patterns (crystal arrays). Among these, the channel-type assembly in which CD molecules are stacked linearly through hydrogen bonding between their hydroxyl groups, forming a cylindrical structure, is attracting attention in a wide range of fields such as separation/analysis, pharmaceuticals, and cosmetics, as it can be used for substance separation and drug carriers using its channel cavities. So far, by dropping a solution of CD into a specific poor solvent, nano- and microstructures of various shapes such as cubes, wires, rods, and plates, composed of channel-type assemblies of CD molecules, have been easily created. These supramolecular structures are also known to change their shape in response to external stimuli such as heating and exposure to steam. Also, cube-shaped microstructures have been found to demonstrate inclusion ability for chlorinated aromatic compounds mixed into insulating oil and can also gel various organic solvents and oils.