A particle detector includes: a conductive nanolayer; insulating nanolayers attached to both sides of the conductive nanolayer; a nanopore formed to penetrate the conductive nanolayer and the insulating nanolayers so as to provide a migration path for a sample particle; a power supply unit configured to apply an electric field between both ends of the nanopore so as to apply a potential to the conductive nanolayer; and an electric signal measuring unit electrically connected to the conductive nanolayer and configured to measure the potential change in the conductive nanolayer induced by the sample particle as the sample particle migrates through the nanopore. The particle detector is capable of detecting a particle with high signal-to-noise ratio and resolution, scanning a sample without mechanical motion of the conductive nanolayer and analyzing DNA base sequences.