Abstract: Disclosed is a method in which flat layers are produced in succession so each newly produced layer is stacked on a previously produced layer or on a flat metal support, each layer having at least one metal strip occupying the entire thickness of the corresponding layer. The production of each layer includes: deposition, during which part of the strip is pressed against the previously produced layer or the support; a fusion step carried out during the deposition step during which only a fused portion of the part is fusion-welded to the previously produced layer or to the support; and repeating the deposition and fusion steps, applying them to corresponding parts of the or each strip offset from each other along a second axis perpendicular to the first axis, such that the fused portions of two of the parts following each other along the second axis overlap.