A review of the main causes of changes of cometary radiance spectra is given in this paper. In the study various
states of the surface of nucleus and dust and gases in the coma are considered. The influence of the gases, materials, the dimensions and temperature of grains on the surface of the nucleus and in the inner coma are analysed.
The influence of solar irradiance and zenith angle are also taken into account. Some remarks how to distinguish between the surface of nucleus and the coma contribution to the spectral features are presented. Moreover, a few examples of spectra combined with radiative transfer codes which take into account the cumulative effect of the surface of nucleus and the inner coma containing gases and dust are shown. The presented study is directly connected with spectrometric measurements to be carried out during Rosetta mission to the Comet P/Wirtanen.