Accurate and sensitive sequencing in pyrosequencing is achieved by allowing complementary strand synthesis reaction to proceed homogeneously and completely in a short time while performing luminescence reaction for a sufficiently long time. DNA as a sequencing target is immobilized on the surface of a solid support. Nucleic acid substrates are injected from a dispenser to the support site where complementary strand synthesis is in turn performed rapidly and completely in a short time under a small reaction volume. Next, the support together with the product thereon is moved into a luminescence reaction solution where luminescence reaction is in turn performed. Thus, a DNA complementary strand synthesis reaction site and a luminescence reaction site are completely separated. The support surface is also washed by dipping the support in the luminescence reaction solution that contains a luminescence reagent and an enzyme that degrades redundant nucleic acid substrates.