A linear electromagnetic actuator has a stroke c, with at least one stable position in one of the ends of the stroke, and includes: an armature made of a soft magnetic material, the armature being movable in an axial direction Y and having a length Hm in the direction Y, the armature having a symmetrical shape at the axis Y, and a stationary stator yoke made of a soft magnetic material and holding at least one electric coil. The actuator also includes at least one stationary permanent magnet that is magnetized along a transverse axis X perpendicular to the direction Y. The magnet is transversely placed between the movable armature and the electric coil. The magnet has a length Ha in the direction Y. The stationary yoke and the movable armature define therebetween at least one axial air gap. Ha+c is of the order of magnitude of Hm. The length Hm is such that 0.9×(Ha+c)