We report on the design and characterization of a
grazing-incidence flat-field spectrograph that allows
simultaneously the measurement of spectrum, beam divergence,
and absolute flux of EUV and soft X-ray radiation for a beam
of high-order laser harmonics generated by the interaction between
an ultrashort femtosecond laser pulse and a gas jet. The instrument
seems a very powerful tool for the understanding of the generation
process.