Numerical simulation in electrical engineering allows reducing development costs by predicting device performance. An accurate prediction often requires 3D models, inducing high storage capacity and CPU power needs. As computation times can be very important, parallel computers are well suited for these models. 3D simulation in electrical engineering is based on recent research work (Whitney's elements, auto-gauged formulations, discretization of the source terms) and it results in complex and irregular codes using sparse matrices, where data accesses are done via indirect addressing. In this paper, we present the results of the parallelization of a 3D magnetostatic code using High Performance Fortran (HPF). This high level programming language allows a simple and efficient approach of parallel machines. It provides both an easier maintenance of the codes and higher software productivity for electrical engineers.