A process for the UV-LIGA fabrication of a multilayer metal structure comprising a first layer having a hole or a recess, at least a second layer adjacent to a first layer, not entirely superposed therewith and directly above said hole or recess, which process comprises the following steps: a) a photoresist layer is spread over a flat substrate made of solid metal, b) the photoresist layer is heated, if necessary to evaporate the solvent, c) the photoresist layer is exposed to an irradiation through a mask corresponding to the desired impression, d) if necessary to complete the photocuring or photodecomposition of the irradiated parts, an annealing operation is carried out on the layer obtained from the step c), e) the development step is carried out, by dissolving the parts that have not undergone photocuring or photodecomposition, so as to obtain a cured photoresist mold, f) a first layer of a metal or alloy is galvanically deposited in the open parts of the mold, and the metal structure is leveled by machining, g) steps a), b), c), d) and e) are repeated, h) a second layer of a metal or alloy is galvanically deposited, and the metal structure and the mold are leveled by machining so as to obtain a planar upper surface, i) if necessary, steps g) and h) are repeated so as to form the desired multilayer metal structure; and j) the multilayer metal structure obtained and the cured photoresist are detached from the substrate by delaminating, the photoresist is separated so as to free the multilayer metal structure characterized in that, - at step c), the irradiation is a UV irradiation of 100 to 2000 mJ/cm 2 measured at a wavelength from 365 nm, - at step f), the metal structure and the mold are leveled by machining, then a metal tie layer is deposited by vacuum evaporation on the entire planar upper surface, and - at the end of step j), that part of the metal tie layer or layers which has not been inserted between two electrodeposited metal layers (12, 16) is removed. a) a photoresist layer is spread over a flat substrate made of solid metal, b) the photoresist layer is heated, if necessary to evaporate the solvent, c) the photoresist layer is exposed to an irradiation through a mask corresponding to the desired impression, d) if necessary to complete the photocuring or photodecomposition of the irradiated parts, an annealing operation is carried out on the layer obtained from the step c), e) the development step is carried out, by dissolving the parts that have not undergone photocuring or photodecomposition, so as to obtain a cured photoresist mold, f) a first layer of a metal or alloy is galvanically deposited in the open parts of the mold, and the metal structure is leveled by machining, g) steps a), b), c), d) and e) are repeated, h) a second layer of a metal or alloy is galvanically deposited, and the metal structure and the mold are leveled by machining so as to obtain a planar upper surface, i) if necessary, steps g) and h) are repeated so as to form the desired multilayer metal structure; and j) the multilayer metal structure obtained and the cured photoresist are detached from the substrate by delaminating, the photoresist is separated so as to free the multilayer metal structure - at step c), the irradiation is a UV irradiation of 100 to 2000 mJ/cm 2 measured at a wavelength from 365 nm, - at step f), the metal structure and the mold are leveled by machining, then a metal tie layer is deposited by vacuum evaporation on the entire planar upper surface, and - at the end of step j), that part of the metal tie layer or layers which has not been inserted between two electrodeposited metal layers (12, 16) is removed.