A 180° deflection toroidal analyzer is developed for a simultaneous angle and energy analysis of the electron discharged from the solid surface. The measurements in angle-resolved photo- and Auger electron spectroscopy in a short time are possible with this analyzer. In present research, we designed the optimum input-lens-system for improvement of focusing properties and estimated it by experimental comparison with the former designed one. According to the FWHM diagram of the energy distribution of electron elastically scattered from Ag(111) surfaces, the optimum lens system has smaller aberration for retarding ratio with wide range of 2-30. In addition, it turned out that the deflection field in lens system compensated for the fringe field and optimized the trajectories in the analyzer, and these results were in good agreement with those obtained by trajectory simulation. Moreover, under the experiment condition based on the above-mentioned examination, we measured the two-dimensional pattern of O KLL Auger electron diffraction from MgO(001) surface.