Magnetic field distribution is determined by applying Equivalent Currents Method (ECM). The Green's function for magnetic vector potential of the infinite linear conductor with steady current, placed in free space, on the boundary of two magnetic materials, is used. In this paper, the authors applied a technique based on substituting Ampere's microscopic currents with total currents. Due to combination of numerical and analytical determination, this is a hybrid method. Together with Equivalent Electrode Method (EEM), this method can be applied for magnetic field calculations of systems with both metal electrodes and many different homogenous magnetic materials.