The electron beam melting (EBM) is one of the most promising metal powder-bed based additive manufacturing technologies. In recent years, a greater awareness of the advantages and limitations of this technology has been acquired, which have allowed its diffusion in the manufacturing world. In this context, process simulation plays a fundamental role in the process parameters optimisation for material development. The thesis work begins with an overview on the EBM process simulation. The overview highlights the main advantages and limitations according to the current computational resources. Some guidelines for the implementation of simulation models are outlined and the main degrees of freedom according to the EBM process are presented.