Method for producing a multi-layer for a probe card for a testing apparatus for electronic devices, comprising the steps of: - providing a plurality of dielectric layers (30a-30n) starting from a first dielectric layer to a last dielectric layer; - realizing, by laser ablation, in each dielectric layer (30a, 30b) of said plurality of dielectric layer (30a-30n) a plurality of pass-through structures (31a, 31b) occurring in matching number in each dielectric layer in (30a, 30b), said matching number of pass-through structures (31a, 31b) being adapted to put into contact opposite faces of each dielectric layer (30a, 30b); - filling said plurality of pass-through structures (31a, 31b) through a conductive material to realize in each dielectric layer (30a, 30b) a plurality of conductive structures (34a, 34b); and - superimposing said plurality of dielectric layers (30a-30n) in a way that each conductive structure of said plurality of conductive structures of each dielectric layer is in contact with a corresponding conductive structure of said plurality of conductive structures of a subsequent and contiguous dielectric layer in said multi-layer and forms a plurality of conductive paths; said conductive paths establishing an electrical connection between a first plurality of contact pads realized on a first face of said multi-layer in correspondence of an exposed face of said first dielectric layer and a second plurality of contact pads realized on a second and opposite face of said multi-layer, in correspondence of an exposed face of said last dielectric layer, said second plurality of contact pads having a greater pitch than said first plurality of contact pads, said multi-layer thus performing a spatial transformation between said plurality of contact pads (30A, 30B) connected through said connective paths, characterized in that said step of realizing in each dielectric layer (30a, 30b) said plurality of pass-through structures (31a, 31b) comprises a step of realizing at least one pass-through hole (32a, 32b), said pass-through hole (32a, 32b) transversally extending and connecting opposite faces of a corresponding dielectric layer (30a, 30b), and wherein said step of realizing in each dielectric layer (30a, 30b) said plurality of pass-through structures (31a, 31b) further comprises a step of realizing at least one recess (33a, 33b), said recess (33a, 33b) longitudinally extending starting from said pass-through hole (32a, 32b) at the surface of said dielectric layer (30a, 30b). - providing a plurality of dielectric layers (30a-30n) starting from a first dielectric layer to a last dielectric layer; - realizing, by laser ablation, in each dielectric layer (30a, 30b) of said plurality of dielectric layer (30a-30n) a plurality of pass-through structures (31a, 31b) occurring in matching number in each dielectric layer in (30a, 30b), said matching number of pass-through structures (31a, 31b) being adapted to put into contact opposite faces of each dielectric layer (30a, 30b); - filling said plurality of pass-through structures (31a, 31b) through a conductive material to realize in each dielectric layer (30a, 30b) a plurality of conductive structures (34a, 34b); and - superimposing said plurality of dielectric layers (30a-30n) in a way that each conductive structure of said plurality of conductive structures of each dielectric layer is in contact with a corresponding conductive structure of said plurality of conductive structures of a subsequent and contiguous dielectric layer in said multi-layer and forms a plurality of conductive paths;