Abstract: An electromagnetic acutator device for selecting needles in a knitting machine comprises two windings (3,4) positioned on opposite sides relative to an armature (5) in a support structure (2) made from a ferromagnetic material. The armature (5), which is also made from a ferromagnetic material, is hinged onto the structure (2), according to an axis substantially perpendicular to the axis of the windings (3,4) and is subject to the action of the magnetic filed generated by the windings (3,4) in order to be moved between two angular positions. The armature is hinged at one end engages a selection lever (11) at its other end, and has a configuration with two transversal portions (19, 20) protruding from opposite sides, and penetrating inside the interior of the windings (3,4).