The process comprises the following steps: a) a first element (3) or a plurality of said first elements (3) is/are machined in a first silicon wafer (1) keeping said elements (3) joined together via material bridges (5); b) step a) is repeated with a second silicon wafer (2) in order to machine a second element (4), differing in shape from that of the first element (3), or a plurality of said second elements (4); c) the first and second elements (3, 4) or the first and second wafers (1, 2) are applied, face to face, with the aid of positioning means (6, 7); d) the assembly formed in step c) undergoes oxidation; and e) the parts (10) are separated form the wafers (1, 2). Micromechanical timepiece parts obtained according to the process.