A method of enclosing a microscopic body in at least some of a plurality of cavities , that are formed in a bottom surface of a well that is formed in a substrate , and that are separated from each other, the method comprising: a first step of arranging an insertion member in the space of the well above a cavity-formed surface of the substrate , determining relative positions of the insertion member and the substrate by a support section provided on the insertion member such that a bottom surface of the insertion member and the cavity-formed surface of the substrate face each other, thereby providing a solution introduction space between the bottom surface of the insertion member and the cavity-formed surface of the substrate , and providing a solution discharge space that is in communication with the solution introduction space , the solution discharge space being located above the bottom surface of the insertion member , and between the substrate and the insertion member , within the substrate , and/or within the insertion member ; a second step of introducing a first liquid (S1) into the solution introduction space , wherein the first liquid (S1) includes the microscopic body and a first solvent; and a third step of introducing a second liquid (S2) into the solution introduction space , wherein the second liquid (S2) includes a second solvent immiscible with the first solvent, discharging, into the solution discharge space , the first liquid (S1) introduced into the solution introduction space as a portion of the first liquid (S1) introduced into the solution introduction space and the cavities , and thereby forming, within each cavity , a droplet of the first liquid (S1) coated with the second liquid (S2) and containing the microscopic body. a first step of arranging an insertion member in the space of the well above a cavity-formed surface of the substrate , determining relative positions of the insertion member and the substrate by a support section provided on the insertion member such that a bottom surface of the insertion member and the cavity-formed surface of the substrate face each other, thereby providing a solution introduction space between the bottom surface of the insertion member and the cavity-formed surface of the substrate , and providing a solution discharge space that is in communication with the solution introduction space , the solution discharge space being located above the bottom surface of the insertion member , and between the substrate and the insertion member , within the substrate , and/or within the insertion member ; a second step of introducing a first liquid (S1) into the solution introduction space , wherein the first liquid (S1) includes the microscopic body and a first solvent; and a third step of introducing a second liquid (S2) into the solution introduction space , wherein the second liquid (S2) includes a second solvent immiscible with the first solvent, discharging, into the solution discharge space , the first liquid (S1) introduced into the solution introduction space as a portion of the first liquid (S1) introduced into the solution introduction space and the cavities , and thereby forming, within each cavity , a droplet of the first liquid (S1) coated with the second liquid (S2) and containing the microscopic body. <EOS>