Provided is a spectrum processing apparatus for removing noise, caused by a change in external environment, from a spectrum obtained by a spectrometer. The spectrum processing apparatus includes: a spectrometer configured to measure a first spectrum according to a change in external environment from a first object, and to measure a second spectrum for component analysis from a second object; and a processor configured to extract, based on the first spectrum, an eigenvector for each wavelength according to the change in external environment, and to obtain a final spectrum by correcting the second spectrum based on the extracted eigenvector for each wavelength.