This research project is a global study of the metal additive manufacturing from the optimization of the design phase to the improvement of the final state of the parts with finishing treatments and passing by the adjustment of the production process. It starts with a state of art of the technologies, materials and industrial projects leading to focus on the laser melting of a metallic powder bed. The study of the manufacturing process has been realised focusing on the laser’s parameters: its speed and power. The optimization has been made with the objective of improving the surface state of the parts as long as the production was concerning dental implants in Cobalt-Chromium alloy. The design phase has been focused on with the topological optimization method applied to a suspension’s triangle in stainless steel. This method leading to a reduction of the mass and/or gain of stiffness of the part is used a lot with the additive manufacturing as long as it permits complex geometries. It although has to be linked to real tests to get information like the mechanical characteristics necessary for the simulation and to validate or not the resistance of the new geometry. The improvement of the final state of the parts can be related to the surface aspect with the shot peening process but although to the internal state of the part with post heat treatments. Here various heat treatments have been realised on a stainless steel, an aluminium alloy and a Nickel based superalloy to reduce the internal residual stresses and improve the homogeneity of the parts. Different macro and microscopic characterisations have been realised to validate or not the effect of the treatments on the quality of the samples to avoid their deformation and break and to try to approach the characteristics of a part issued from a more classical metal manufacturing process