A method for detecting a target nucleic acid sequence in a nucleic acid sample by a PCE-IH (PTO Cleavage and Extension-Dependent Immobilized Oligonucleotide Hybridization) assay on a solid phase, comprising: (a) hybridizing the target nucleic acid sequence with a PTO (Probing and Tagging Oligonucleotide); wherein the PTO comprises (i) a 3-targeting portion comprising a hybridizing nucleotide sequence complementary to the target nucleic acid sequence and (ii) a 5'-tagging portion comprising a nucleotide sequence non-complementary to the target nucleic acid sequence; wherein the 3-targeting portion is hybridized with the target nucleic acid sequence and the 5'-tagging portion is not hybridized with the target nucleic acid sequence; (b) contacting the resultant of the step (a) to the enzyme having a 5' nuclease activity under conditions for cleavage of the PTO; wherein the PTO is cleaved by the enzyme having the 5' nuclease activity such that the cleavage releases a fragment comprising the 5'-tagging portion or a part of the 5'-tagging portion of the PTO; (c) hybridizing the fragment released from the PTO with a CTO (Capturing and Templating Oligonucleotide); wherein the CTO comprises in a 3'to 5' direction (i) a capturing portion comprising a nucleotide sequence complementary to the 5'-tagging portion or a part of the 5'-tagging portion of the PTO and (ii) a templating portion comprising a nucleotide sequence non-complementary to the 5'-tagging portion and the 3'-targeting portion of the PTO; wherein the fragment released from the PTO is hybridized with the capturing portion of the CTO; (d) performing an extension reaction using the resultant of the step (c) and a template-dependent nucleic acid polymerase; wherein the fragment hybridized with the capturing portion of the CTO is extended to produce an extended strand containing an extended sequence complementary to the templating portion of the CTO and an extended duplex is formed; wherein the extended strand comprises a label; (e) hybridizing the extended strand with an IO (immobilized oligonucleotide) immobilized on a solid substrate; wherein the IO comprises a sequence complementary to the extended strand; wherein the hybridization between the extended strand with the IO provides a detectable signal on the solid substrate; wherein the sequence of the IO is selected not to form a hybrid with an undigested PTO and (f) detecting the signal indicative of the presence of the extended strand; the presence of the extended strand indicates the presence of the target nucleic acid sequence. (a) hybridizing the target nucleic acid sequence with a PTO (Probing and Tagging Oligonucleotide); wherein the PTO comprises (i) a 3-targeting portion comprising a hybridizing nucleotide sequence complementary to the target nucleic acid sequence and (ii) a 5'-tagging portion comprising a nucleotide sequence non-complementary to the target nucleic acid sequence; wherein the 3-targeting portion is hybridized with the target nucleic acid sequence and the 5'-tagging portion is not hybridized with the target nucleic acid sequence; (b) contacting the resultant of the step (a) to the enzyme having a 5' nuclease activity under conditions for cleavage of the PTO; wherein the PTO is cleaved by the enzyme having the 5' nuclease activity such that the cleavage releases a fragment comprising the 5'-tagging portion or a part of the 5'-tagging portion of the PTO; (c) hybridizing the fragment released from the PTO with a CTO (Capturing and Templating Oligonucleotide); wherein the CTO comprises in a 3'to 5' direction (i) a capturing portion comprising a nucleotide sequence complementary to the 5'-tagging portion or a part of the 5'-tagging portion of the PTO and (ii) a templating portion comprising a nucleotide sequence non-complementary to the 5'-tagging portion and the 3'-targeting portion of the PTO; wherein the fragment released from the PTO is hybridized with the capturing portion of the CTO; (d) performing an extension reaction using the resultant of the step (c) and a template-dependent nucleic acid polymerase; wherein the fragment hybridized with the capturing portion of the CTO is extended to produce an extended strand containing an extended sequence complementary to the templating portion of the CTO and an extended duplex is formed; wherein the extended strand comprises a label; (e) hybridizing the extended strand with an IO (immobilized oligonucleotide) immobilized on a solid substrate; wherein the IO comprises a sequence complementary to the extended strand; wherein the hybridization between the extended strand with the IO provides a detectable signal on the solid substrate; wherein the sequence of the IO is selected not to form a hybrid with an undigested PTO and (f) detecting the signal indicative of the presence of the extended strand; the presence of the extended strand indicates the presence of the target nucleic acid sequence.