Method for manufacturing a three-dimensional object from a stack of layers of powder, said three-dimensional object comprising an outer skin and an inner three-dimensional mesh, said object being formed by a superpositioning of several layers of powder, each comprising at least one outer border enclosing a central part comprising an inner mesh comprising grid cells (31, 32, 33), the superpositioning of the outer borders of the layers forming said outer skin of the object and the superpositioning of the inner meshes of the layers forming said inner three-dimensional mesh of the object, a method wherein: a) a layer of powder is deposited with a total surface area S1 on a working plate; b) an energy beam is used to perform a full scan of a surface S2 contained within said total surface area S1, as a function of the three-dimensional object to be manufactured, so as to form micro-connections between the grains of powder of said surface area S2; c) during a first step of melting-solidification, said energy beam is used to perform the melting of the outer border or of the inner mesh, the latter penetrating into a part of the width of said outer border; d) during a second step of melting-solidification, said energy beam is used to perform the melting of the element chosen from among the outer border or the inner mesh which has not been solidified during said first step of melting-solidification, so as to melt the part of said mesh penetrating into said outer border twice; e) the steps a) to d) are repeated n times so as to form n superposed layers of metallic powder and manufacture said three-dimensional object, wherein, between said grid cells (31, 32, 33) of the inner mesh, the grains or particles of powder do not undergo any melting but are micro-welded with one another by means of the micro-connections; f) a hot isostatic compression of the three-dimensional object is performed. a) a layer of powder is deposited with a total surface area S1 on a working plate; b) an energy beam is used to perform a full scan of a surface S2 contained within said total surface area S1, as a function of the three-dimensional object to be manufactured, so as to form micro-connections between the grains of powder of said surface area S2; c) during a first step of melting-solidification, said energy beam is used to perform the melting of the outer border or of the inner mesh, the latter penetrating into a part of the width of said outer border; d) during a second step of melting-solidification, said energy beam is used to perform the melting of the element chosen from among the outer border or the inner mesh which has not been solidified during said first step of melting-solidification, so as to melt the part of said mesh penetrating into said outer border twice; e) the steps a) to d) are repeated n times so as to form n superposed layers of metallic powder and manufacture said three-dimensional object, wherein, between said grid cells (31, 32, 33) of the inner mesh, the grains or particles of powder do not undergo any melting but are micro-welded with one another by means of the micro-connections; f) a hot isostatic compression of the three-dimensional object is performed.