A method for manufacturing a metal part, remarkable in that it comprises the following steps aiming at: - manufacturing a tooling assembly comprising: o at least one counter-form (101, 321a, 321b) with a shape substantially similar to that of said part to be manufactured, and o at least one tight core (103, 203, 327) at least partially deformable and comprising: ▪ at least one inner skin (109, 315a, 315b) and at least one outer skin (105, 205, 313a, 313b), said inner and outer skins constituting respectively an inner skin and an outer skin of the part to be manufactured, ▪ at least one honeycomb structure (107, 207, 323, 325) positioned between said inner and outer skins, ▪ at least one brazing member, inserted between the honeycomb structure (107, 207, 323, 325) and said inner (109, 315a, 315b) and outer (105, 205, 313a, 313b) skins, said core being closed at its ends by at least one tight lid (111, 113, 317, 319) comprising means for introducing a gas inside said core, at least one of said lids being fastened to said inner skin by welding; - positioning said tooling assembly in a vacuum furnace; - introducing a pressurized gas directly within the inner skin of the core of the tooling assembly; - heating the tooling assembly so as to cause successively: o the plating of the core against the counter-form (101, 321 a, 321 b) by expansion of said pressurized gas; o the brazing of the honeycomb structure (107, 207, 323, 325) and of the inner (109, 315a, 315b) and outer (105, 205, 313a, 313b) skins; - purging said gas from the inner portion of the inner skin (109, 315a, 315b); - dismounting the tooling assembly so as to extract the manufactured part. - manufacturing a tooling assembly comprising: o at least one counter-form (101, 321a, 321b) with a shape substantially similar to that of said part to be manufactured, and o at least one tight core (103, 203, 327) at least partially deformable and comprising: ▪ at least one inner skin (109, 315a, 315b) and at least one outer skin (105, 205, 313a, 313b), said inner and outer skins constituting respectively an inner skin and an outer skin of the part to be manufactured, ▪ at least one honeycomb structure (107, 207, 323, 325) positioned between said inner and outer skins, ▪ at least one brazing member, inserted between the honeycomb structure (107, 207, 323, 325) and said inner (109, 315a, 315b) and outer (105, 205, 313a, 313b) skins, o at least one counter-form (101, 321a, 321b) with a shape substantially similar to that of said part to be manufactured, and o at least one tight core (103, 203, 327) at least partially deformable and comprising: ▪ at least one inner skin (109, 315a, 315b) and at least one outer skin (105, 205, 313a, 313b), said inner and outer skins constituting respectively an inner skin and an outer skin of the part to be manufactured, ▪ at least one honeycomb structure (107, 207, 323, 325) positioned between said inner and outer skins, ▪ at least one brazing member, inserted between the honeycomb structure (107, 207, 323, 325) and said inner (109, 315a, 315b) and outer (105, 205, 313a, 313b) skins, ▪ at least one inner skin (109, 315a, 315b) and at least one outer skin (105, 205, 313a, 313b), said inner and outer skins constituting respectively an inner skin and an outer skin of the part to be manufactured, ▪ at least one honeycomb structure (107, 207, 323, 325) positioned between said inner and outer skins, ▪ at least one brazing member, inserted between the honeycomb structure (107, 207, 323, 325) and said inner (109, 315a, 315b) and outer (105, 205, 313a, 313b) skins, - positioning said tooling assembly in a vacuum furnace; - introducing a pressurized gas directly within the inner skin of the core of the tooling assembly; - heating the tooling assembly so as to cause successively: o the plating of the core against the counter-form (101, 321 a, 321 b) by expansion of said pressurized gas; o the brazing of the honeycomb structure (107, 207, 323, 325) and of the inner (109, 315a, 315b) and outer (105, 205, 313a, 313b) skins; o the plating of the core against the counter-form (101, 321 a, 321 b) by expansion of said pressurized gas; o the brazing of the honeycomb structure (107, 207, 323, 325) and of the inner (109, 315a, 315b) and outer (105, 205, 313a, 313b) skins; - purging said gas from the inner portion of the inner skin (109, 315a, 315b); - dismounting the tooling assembly so as to extract the manufactured part.