A read-only recording medium for achieving a carrier-to-noise ratio (CNR) using a super-resolution near-field structure (Super-RENS) on which information has been prerecorded includes a substrate having the information recorded on its surface, a reflective layer formed from a phase change material on the substrate, a first dielectric layer formed on the reflective layer, and a mask layer formed from metal oxide or nanoparticles on the first dielectric layer.