This paper presents the simulation and mathematical modelling of electrostatically actuated fixed–fixed micro-beams used for RF MEMS switches. The simulation of fixed–fixed beams is performed using CoventorWare™ for various beam materials, geometrical variations and gaps. The results of these simulation is validated by solving the Euler’s Beam equation of these micro mechanical structures through discrete mathematical methods. The modelling of these micro mechanical structures will give insight into the various parameters of the beam structure affecting the displacement of the structure with applied voltages. Galerkin’s technique has been used to validate the pull-in obtained through simulations. This method has been validated for around 30 cases.