Following the principles proposed by workers at Berkeley University, we have developed a version of the electrostatic micromotor based on the sacrificial layer method combined with oxidation of the rotor. In order to study the behaviour of this electrostatic micromotor, we have elaborated two softwares. The first, called EFCREL, is to simulate the static operation of the electrostatic micromotors and the second, called EFDYN, is to simulate their dynamic operation. Both are based on a finite-element code, called EFCAD, for electromagnetic field computation. They help us with the design of the fabricated micromotor and the simulation of its dynamic working, respectively. The elaboration of these two softwares represents our first steps towards a fully integrated CAD (computer aided design) system for micromotors.