A method for simultaneously detecting or quantifying two or more different target nucleic acids contained in a sample by chromatography, wherein the method comprises: (a) hybridizing oligonucleotides M1', M2', M3', and M4' to regions M1, M2, M3, and M4, respectively, in a single-stranded region of a target nucleic acid N 1 , wherein the target nucleic acid N 1 comprises a region R1 that is positioned between the regions M1 and M2, and a region R2 that is different from the region R1 and positioned between the regions M3 and M4, wherein the oligonucleotides M1', M2', M3', and M4' comprise a nucleotide sequence complementary to the regions M1, M2, M3, and M4, respectively; (b) hybridizing an oligonucleotide R1' labeled with a label L1 to the region R1, wherein the oligonucleotide R1' comprises a nucleotide sequence complementary to said region; (c) hybridizing an oligonucleotide R2' to the region R2, wherein the oligonucleotide R2' comprises a nucleotide sequence complementary to said region, and optionally an anchor A at its terminus; and (d) detecting or quantifying a nucleic acid hybrid comprising the target nucleic acid N 1 formed through (a) to (c) using the label L1 as an indicator; and (e) performing said (a) to (d) for a target nucleic acid Nx which is different from the target nucleic acid N 1 for detection or quantification of the target nucleic acid Nx, wherein the chromatography is performed based on capillary action in a development element, using a device which comprises: (i) a development element comprising two or more detection zones for capturing and then detecting or quantifying the respective nucleic acid hybrids, each of which comprises the different target nucleic acid, and (ii) an application zone provided in contact with the development element for applying a sample containing the different two or more target nucleic acids. (a) hybridizing oligonucleotides M1', M2', M3', and M4' to regions M1, M2, M3, and M4, respectively, in a single-stranded region of a target nucleic acid N 1 , wherein the target nucleic acid N 1 comprises a region R1 that is positioned between the regions M1 and M2, and a region R2 that is different from the region R1 and positioned between the regions M3 and M4, wherein the oligonucleotides M1', M2', M3', and M4' comprise a nucleotide sequence complementary to the regions M1, M2, M3, and M4, respectively; (b) hybridizing an oligonucleotide R1' labeled with a label L1 to the region R1, wherein the oligonucleotide R1' comprises a nucleotide sequence complementary to said region; (c) hybridizing an oligonucleotide R2' to the region R2, wherein the oligonucleotide R2' comprises a nucleotide sequence complementary to said region, and optionally an anchor A at its terminus; and (d) detecting or quantifying a nucleic acid hybrid comprising the target nucleic acid N 1 formed through (a) to (c) using the label L1 as an indicator; and (e) performing said (a) to (d) for a target nucleic acid Nx which is different from the target nucleic acid N 1 for detection or quantification of the target nucleic acid Nx, (i) a development element comprising two or more detection zones for capturing and then detecting or quantifying the respective nucleic acid hybrids, each of which comprises the different target nucleic acid, and (ii) an application zone provided in contact with the development element for applying a sample containing the different two or more target nucleic acids. <EOS>