The effect of finite geometrical size and angular divergence of an electron beam on original Resonance X-ray Transition Radiation (RTR) and Diffracted RTR (DTR) has been calculated for 900 MeV electron beam. It is shown that the spectral-angular distributions of RTR and DTR are very sensitive to the geometrical and angular parameters of the electron beam and that it could be used for fine diagnostic of relativistic electron or other charged particle beams.