We propose in this paper novel approach for improving mass resolution in atom probe tomography. Using conventional counter-electrode or microelectrode design, improved mass resolution at half, tenth and 1% of the mass peak maximum is predicted when shaping properly the voltage evaporation pulse. Using a numerical approach, it is shown that a flat top voltage pulse used to trigger the field evaporation with sharp front and leading edges associated with a short tip to counter electrode distance(≈10 μm) strongly minimizes the energy deficits of evaporated ions from the sample, so that energy compensation devices are not necessary to obtain high mass resolution.