Provided is a PNA (Peptide Nucleic Acid) chip in which a probe PNA containing a desired DNA sequence is immobilized on a plastic substrate coated with an epoxy group-containing polymer. Therefore, single-stranded PNAs can be immobilized on a transparent plastic substrate by means of an epoxy group-containing polymer layer in an efficient and cost-effective manner. Fluorescence signal detection based on PNA/DNA hybridization enables identification of SNP (Single Nucleotide Polymorphism).