A structure comprises at least a porous body holding a substance releasably, comprising a capping member for keeping the substance inside the pore and/or on at least a part of the entire surface of the porous body, and a connecting member for connecting the porous body and the capping member separably, the connecting member comprising a biopolymer compound.A method for releasing a substance from the structure set forth comprises the steps of applying stimulation from outside to the structure, and cleaving at least one of the bonding between the connecting member and the capping member and the bonding between the connecting member and the porous member to make the substance releasable from the structure.