An electromagnetic actuator for a medical instrument including: a stator and a movable element, at least partly composed of a paramagnetic and/or a ferromagnetic material, and which can be reversibly moved from a first to a second position by the application of a switchable magnetic field, wherein the stator and the movable element have annular distal and proximal pole shoes corresponding to each other, wherein the distal pole shoes and/or the proximal pole shoes of the stator and the movable element are aligned with each other in an overlapping manner in the first and/or the second position, and the distal pole shoes and/or the proximal pole shoes of the stator and the movable element have a structure in the circumferential direction on the surfaces of pole shoes facing each other, with the structures corresponding to each other.