This paper presents a novel electrostatically actuated microelectromechanical switch. The structure of cantilever beam with electrodes sandwiched between Si and SiO2 layers has been established. Placing the pull-down electrodes outside the switching contact, the actuation voltage can be reduced while keeping high contact force and restoration force. The top and bottom dielectric materials separated two conducting electrodes when actuated. Thus, the reliability and the performance of the switch have been greatly improved. The charts of the deflection of the cantilever beam with respect to the voltage have been simulated with the MATLAB computer programming language.