  The QCD analysis of deep inelastic diffractive scattering at HERA is
performed assuming the dominance of the "soft" pomeron exchange and simple,
physically motivated parametrization of parton distributions in the pomeron.
  Both the LO and NLO approximations are considered and the theoretical
predictions concerning the quantity $R=F_L^D/F_T^D$ for diffractive structure
functions are presented.
