Flux3D, a finite element package for magnetic computation. In this paper, we describe a finite element package for the computation of three-dimensional magnetostatic field. The finite element mesh is automatically built in two steps using a Delaunay tetrahedrization Step 1. The user gives interactively a first set of nodes located on interfaces and boundaries, and the program compute a coarse tetrahedral mesh Step 2. The program adds new nodes automatically to refine the initial mesh and regularizes it. The implemented finite element formulations use either scalar or vector potential. The post processor allows interactive computation and visualization of any local or global quantities given by closed formulae.