Disclosed herein is a method for detecting DNA using a nanopore including treating the surface of a nanopore formed in a solid substrate with a substance carrying positive charges; introducing a DNA-containing sample into the surface-treated nanopore; and detecting electrical signals generated during translocation of the sample through the nanopore. Also disclosed herein is device for detecting DNA using a nanopore including a solid substrate including a nanopore, treated with a substance which carries positive charges to change a surface property of the nanopore so that the nanopore surface carries positive charges; an electrode applying voltage to the nanopore of the solid substrate; and a measurement unit measuring an electrical signal generated during translocation of a DNA-containing sample through the nanopore.