  We consider an analytic approach to the elucidation of the role played by
Coulomb interaction in the formation of the spectrum and angular distributions
of the electrons produced by above threshold ionization of the atoms. Our
approach is based on allowance for the multiple scattering of a photoelectron
by the Coulomb potential of the residual ion, with pickup of a field photon in
each scattering act. The amplitude of a process with direct ionization of the
atom and subsequent scattering of the photoelectron in the continuum by the
Coulomb potential of the residual ion are found.
