A magnetic microactuator (100) including a coil (6; 61; 62) controlling the axial movement of a sliding block (30) including at least one permanent magnet (2) joined or aligned with a ferromagnetic or magnetised rear arbor (42) and guiding the field lines of the magnetic field of revolution in the axial direction (D) through the coil (6; 61; 62) wherein circulates the sliding block (30), up to a rear end (43) of said rear arbor (42) that tends to cooperate by magnetic attraction with at least one first ferromagnetic restoration element (8), located in the vicinity of a rear face (25) of the structure (20) of the microactuator (100), in order to bring said sliding block (30) back into a rear end-of-travel position when no coil (6; 61; 62) is powered.