A device is provided for capturing a nucleic acid in a single cell, having: a two-dimensional array comprising a substrate, a plurality of single cell capturing holes provided on one surface of the substrate, and a nucleic acid capturing region comprising, on the inside of the substrate, a nucleic acid capturing body, which is configured to capture the nucleic acids extracted from the individual cells respectively captured by the single cell capturing hole; a flow channel which is provided adjacent to the nucleic acid capturing region of the substrate, and is configured to discharge a solution in the nucleic acid capturing region; and a cylindrical structure body which is arranged on the substrate at the time of introducing a cell suspension and encloses a plurality of the single cell capturing holes, wherein the cylindrical structure body is removed after the cells are captured by the single cell capturing holes.