  We study the target normal spin asymmetry for the reaction $ep \to ep$ at
electron energy up to few GeV in the laboratory frame. The asymmetry is
proportional to the imaginary part of the reaction scattering amplitude. To
estimate the imaginary part of the amplitude we use the unitarity relation and
saturate the intermediate hadron states by the proton and resonances from the
first, second and third resonance regions. The resonance electromagnetic
transition amplitudes, needed to evaluate the asymmetry, are taken from
experiment.
