Electrostatic lenses are established using billed electrodes with cylinder bores which are exactly organized on a line of symmetry. In this paper, four designs of three-element cylindrical electrostatic lenses in the acceleration and deceleration mode with different geometrical shapes were created to prove how the operational characteristics of the lenses are affected by the electrode geometry according to potentials, the electron beam diameter in the image plane, kinetic energy, velocity, and acceleration before and after the electron beam passes through each of the four lenses. The best lens is chosen from the four lenses based on its optical performance. It has been found that the lens with the concave outer electrode surface has the best optical performance as an accelerating lens, and the lens with the concave inner electrode surface has the best optical performance as a decelerating lens. It was discovered that the geometry of the electrodes plays a major role in minimizing the beam electron diameter at the image plane and in accelerating and decelerating the electron beam. The calculations are carried out by using the SIMION8.0 and SL Tools Programs package.