Disclosed is a spectroscopic device including a planar lightwave circuit to which light passing through an optical fiber is input, a wavelength divider configured to divide a wavelength of light passing through the planar lightwave circuit, a beam splitter configured to divide a traveling direction of light passing through the wavelength divider into an external sample inlet and an internal sample inlet and adjust power of the divided light, a charge-coupled device (CCD) image sensor configured to covert light transmitted from the internal sample inlet to an electrical signal or convert light reflected by the external sample inlet to an electrical signal, a control and signal processor configured to process the electrical signal to indicate a light intensity based on each wavelength, and an input and output interface configured to perform a spectrum analysis for each wavelength using the processed electrical signal.