A BaF2 scintillation spectrometer has been constructed for the determination of photon energy spectra in workplaces around nuclear facilities. Energy absorption spectra by the BaF2 detector were calculated with the EGS4 Monte Carlo code in the energy region from 0.1 to 100MeV and a response matrix of the spectrometer was obtained from the energy absorption spectra, of which the energy resolutions were modified to fit to the experimental results. With the irradiation experiments using neutron-capture gamma rays and those from radioactive sources, it became clear that photon energy spectra can be evaluated within an error of about 10% in the energy region 0.1MeV to a few tens of megaelectronvolts.
