Provided are an apparatus and method for detecting biomaterials. The apparatus for detecting the biomaterials includes a light source unit, a biomaterial reacting unit, and a detection unit detecting. The light source unit provides incident light. The biomaterial reacting unit includes a substrate and metal nanoparticles spaced from the substrate. The surface plasmon resonance phenomenon is induced on surfaces of the metal nanoparticles by the incident light. First detecting molecules specifically binding to target molecules are immobilized to the surfaces of the metal nanoparticles. The detection unit detects a resonance wavelength of emission light emitted from the metal nanoparticles by the surface plasmon resonance phenomenon.