Abstract : The reconstruction of the complex permittivity profile of inhomogeneous objects from measured scattered field data is a strongly nonlinear and ill-posed problem. Generally, the quality of the reconstruction from noisy data is enhanced by the introduction of a regularization scheme. Starting from an iterative algorithm based on a conjugate gradient method and applied to the nonlinear problem, this paper deals with a new regularization scheme, using edge-preserving (EP) potential functions. With this a priori information, the object to reconstruct is modelled with homogeneous areas separated by borderlike discontinuities. The enhancement is illustrated throughout some examples with noisy synthetic data.