A new approach is proposed for the simulation of electrical conditions in a DC energized wire-duct electrostatic precipitator under dust free conditions. Voltage-current characteristics under clean air conditions are considered as a reference in analyzing the performance of a precipitator. This paper gives the simultaneous solution for the governing Poisson's and current continuity equations using a combined Boundary Element and Finite Difference Method over a one-quarter section of the precipitator. The solution of the domain integral, which represents the effect of space charges in the Poisson's equation, is also simplified using a numerical technique. The significant features of this paper are, reduced problem domain and hence less memory space and cost, less number of iterations and closer agreement of voltage-current characteristics with published experimental data when compared to other methods. The results are validated against the data obtained from experiments conducted by authors on a laboratory scale precipitator at Bharat Heavy Electricals, Ranipet, India. The distribution of electric field and current density along the plate have also been presented and discussed in this paper. (C) 2002 Elsevier Science B.V. All fights reserved.