The paper deals with an eddy current field problem as a case study. The aim is to find the solution of the problem by the help of the Finite Element Method (FEM), and the T, , potential formulation taking the nonlinearity of the material into account. The effect of nonlinearity has been approximated with an inverse tangent type analytical model. The nonlinearity has been handled by the polarization method coupled with the Fixed-point iteration technique. © 2008 Akadémiai Kiadó.