We develop an interferometer which has high spectral sensitivity based on the dispersive property of the semiconductor GaAs in the near-infrared region. Our experiment demonstrates that the spectral sensitivity could be greatly enhanced by adding a slow light medium into the interferometer and is proportional to the group index of the material. Subsequently the factors which influence the spectral sensitivity of the interferometer are analyzed. Moreover, we provide potential applications of such interferometers using the dispersive property of semiconductor in whole infrared region.