An exemplary sensor chip includes a substrate, a metal pattern formed on a side of the substrate that is irradiated with excitation light, and a first substance and a second substance provided near the metal pattern. A first intensity Xa of the first surface-enhanced Raman-scattered light from the first substance and a second intensity Xb of the second surface-enhanced Raman-scattered light from the second substance are detected. An intensity ratio Xc, as obtained by dividing the second intensity Xb with the first intensity Xa, is calculated.
