This device comprises: a casing with an upper surface including a sample-dripping portion receiving a liquid sample containing nucleic acid and being dripped from a nozzle; a reaction tube: outwardly projecting from an end of the casing; including a storage space therein; and being formed so as to be installed within a measurement apparatus; a filter carrying the nucleic acid contained in the liquid sample; a filter-supporting body stored within the casing to support the filter in a manner such that the filter is capable of taking: a contacting position wherein the filter contacts with the liquid sample right below the sample-dripping portion; and a reaction position wherein the filter is positioned within the storage space of the reaction tube; and absorbing material capable of taking: a press-attaching position wherein the absorbing material is press-attached to the filter in the contacting position so that the filter absorbs the liquid sample contacting therewith; and a separating position wherein the absorbing material is removed from the press-attaching position so that the filter is allowed to freely move.