Disclosed is a spectroscope including a plurality of spectroscopic units. At least some of the plurality of spectroscopic units detect an optical signal of incident light at different wavelengths. Each of the spectroscopic units includes a resonator and an optical signal processing unit. The number of optical signal processing units included in the spectroscopic units is changed according to the length of the resonator, thereby improving the optical signal processing efficiency per unit area.COPYRIGHT KIPO 2017