A new finite element method (FEM) approach is used to evaluate transient electric field based on a surge wave in a dissipative open region. Instead of the solution of the basic equations in the time domain, the Laplace transform inversion is used to model planar and axisymmetrical transient fields. The main advantage of this approach consists in the possibility of modeling unbounded regions. Current‐driven electrodes, including electrodes with floating potential, are taken into consideration.