The present paper aimed at designing, optimizing, and simulating the RF MEMS Switch which is stimulated electrostatically. The design of the switch is located on the CoplanarWaveguide (CPW) transmission line. The pull-in voltage of the switch was 2V and the axial residual stress of the proposed design was obtained at 23MPa. In order to design and optimize the geometric structure of the switch, the desired model was extracted based on the objective functions of the actuation voltage and the return loss up-state and also the isolation down-state using the mathematical programming. Moreover, the model was solved by the NSGA-II meta-heuristic algorithm in MATLAB software. In addition, the design requirements and the appropriate levels for designing the switch were obtained by presenting the Pareto front from the beam actuation voltage and also the return loss up-state and isolation down-state. Finally, the RF parameters of the switch were calculated as S11=-2.54dB and S21=-33.18dB at the working frequency of 40GHz by extracting the appropriate parameters of the switch design through simulating a switch designed by the COMSOL Multiphysics software 4.4a and the advanced design system (ADS).