Atom Probe (AP) Tomography is a characterization technique enabling the investigation of matter at the atomic scale. The knowledge of the structure and the chemical composition of the material is fundamental for the development of new technologies adapted to smart applications. In this paper, we get our interest to the Voltage Pulse AP, which works with a high voltage pulse of nanosecond duration. One of the key performance of the AP is to have a sufficient resolution to be able to distinguish close mass peaks or small peaks from the background tail noise. The efficiency of the system is closely related to the voltage pulse shape. By comparing current pulse generators characteristics and investigating the influence of different pulse shapes on characterization of atoms, we will propose a new pulse configuration adapted to AP composed of a homemade solid-state Marx generator and an industrial ultrashort pulse generator. Our objectives are to be able to modulate the voltage pulse and optimize the Mass Spectrum resolution.