A method for analyzing a target nucleic acid in a sample, the method comprising the step of: analyzing the target nucleic acid in the sample by bringing the sample into contact with a label and with a primer that can hybridize to the target nucleic acid, wherein the primer is hybridised to the target nucleic acid by bringing the primer into contact with the sample, thereby causing an amplification reaction of the target nucleic acid, wherein the label is a fluorescent dye moiety that exhibits an exciton effect, and wherein the label is covalently bound to the primer so as to be part of the primer, wherein the primer is a nucleic acid molecule comprising at least one of structures represented by the following formulae,,,,, and: where in the formulae,,,,, and, B is an atomic group having a natural nucleobase (adenine, guanine, cytosine, thymine, or uracil) skeleton or an artificial nucleobase skeleton, E is: (i) an atomic group having a deoxyribose skeleton, a ribose skeleton, or a structure derived from either one of them; or (ii) an atomic group having a peptide structure or a peptoid structure, Z 11 and Z 12 are each a fluorescent dye moiety that exhibits an exciton effect, and may be identical to or different from each other, L 1, L 2, and L 3 are each a linker (a linking atom or a linking atomic group), the main chain length (the number of main chain atoms) thereof is arbitrary, L 1, L 2, and L 3 each may or may not contain each of C, N, O, S, P, and Si in the main chain, L 1, L 2, and L 3 each may or may not contain each of a single bond, a double bond, a triple bond, an amide bond, an ester bond, a disulfide bond, an imino group, an ether bond, a thioether bond, and a thioester bond in the main chain, and L 1, L 2, and L 3 may be identical to or different from each other, D is CR, N, P, P=O, B, or SiR, and R is a hydrogen atom, an alkyl group, or an arbitrary substituent, and b is a single bond, a double bond, or a triple bond, or alternatively, in the formulae and, L 1 and L 2 are each the linker, L 3, D, and b may not be present, and L 1 and L 2 may be bonded directly to B, provided that: in the formulae,, and, E is an atomic group described in item (i), and at least one O atom in a phosphoric acid linkage may be substituted with an S atom; in the formulae,, and, E is an atomic group described in item (ii); and in the formulae and, the respective Bs may be identical to or different from each other, and the respective Es may be identical to or different from each other, wherein the primer is immobilized on a solid phase, the label does not emit light when the primer does not hybridize to the target nucleic acid, whereas the label emits light when the primer has hybridized to the target nucleic acid, and the analysis is carried out by detecting the light emitted from the label and the analysis of the target nucleic acid is carried out by further measuring the degree of amplification of the target nucleic acid in the amplification reaction over time. B is an atomic group having a natural nucleobase (adenine, guanine, cytosine, thymine, or uracil) skeleton or an artificial nucleobase skeleton, E is: (i) an atomic group having a deoxyribose skeleton, a ribose skeleton, or a structure derived from either one of them; or (ii) an atomic group having a peptide structure or a peptoid structure, (i) an atomic group having a deoxyribose skeleton, a ribose skeleton, or a structure derived from either one of them; or (ii) an atomic group having a peptide structure or a peptoid structure, Z 11 and Z 12 are each a fluorescent dye moiety that exhibits an exciton effect, and may be identical to or different from each other, L 1, L 2, and L 3 are each a linker (a linking atom or a linking atomic group), the main chain length (the number of main chain atoms) thereof is arbitrary, L 1, L 2, and L 3 each may or may not contain each of C, N, O, S, P, and Si in the main chain, L 1, L 2, and L 3 each may or may not contain each of a single bond, a double bond, a triple bond, an amide bond, an ester bond, a disulfide bond, an imino group, an ether bond, a thioether bond, and a thioester bond in the main chain, and L 1, L 2, and L 3 may be identical to or different from each other, D is CR, N, P, P=O, B, or SiR, and R is a hydrogen atom, an alkyl group, or an arbitrary substituent, and b is a single bond, a double bond, or a triple bond, in the formulae,, and, E is an atomic group described in item (i), and at least one O atom in a phosphoric acid linkage may be substituted with an S atom; in the formulae,, and, E is an atomic group described in item (ii); and in the formulae and, the respective Bs may be identical to or different from each other, and the respective Es may be identical to or different from each other, wherein the primer is immobilized on a solid phase, the label does not emit light when the primer does not hybridize to the target nucleic acid, whereas the label emits light when the primer has hybridized to the target nucleic acid, and the analysis is carried out by detecting the light emitted from the label and the analysis of the target nucleic acid is carried out by further measuring the degree of amplification of the target nucleic acid in the amplification reaction over time.