The present application relates to a method of manufacturing an ink-jet printhead comprising: providing a silicon substrate (10) including active ejecting elements (11); providing a hydraulic structure layer (20) for defining hydraulic circuits configured to enable a guided flow of ink; providing a silicon orifice plate (30) having a plurality of nozzles (31) for ejection of the ink; assembling the silicon substrate (10) with the hydraulic structure layer (20) and the silicon orifice plate (30); wherein providing the silicon orifice plate (30) comprises: providing a silicon wafer (40) having a planar extension delimited by a first surface (41) and a second surface (42) on opposite sides of the silicon wafer (40); performing a thinning step at the second surface (42) so as to remove from the second surface (42) a central portion (43) having a preset height (H), the silicon wafer (40) being formed, following the thinning step, by a base portion (44) having a planar extension and a peripheral portion (45) extending from the base portion (44), transversally with respect to the planar extension of the base portion (44); and forming in the silicon wafer (40) a plurality of through holes, each defining a respective nozzle (31) for ejection of the ink. The method according to the present invention is characterized in that the silicon wafer (40) is a silicon-on-insulator wafer, wherein the silicon-on-insulator wafer comprises a silicon device layer (38) adjacent to the first surface (41), a silicon handle layer (37) adjacent to the second surface (42) and an insulator layer (39) in-between.