Method for fabricating a three-dimensional object by successive consolidation, layer by layer, of selected regions of a layer of powder, consolidated regions corresponding to successive sections of the three-dimensional object, comprising in order: a—deposit layer of powder onto a support; b—fuse the layer of powder by a first laser energy source so as to obtain a fused layer corresponding to the section of the object and exhibiting a first state of its mechanical properties, c—heat at least a part of the fused layer by a second electron beam energy source to a temperature which follows a controlled variation over time so as to modify the first state of the fused layer and to obtain a consolidated layer with improved mechanical properties, d—repeat the preceding steps until several superposed consolidated layers are formed with improved properties forming the object.