Abstract: An electro-magnet comprising a stationary system having a coil, a core and tationary flux-conductive yokes and with one part movable in longitudinal translation, comprising one permanent magnet whose magentizing axis is perpendicular to the moving direction of said movable part and two flux-conductive armatures secured to each pole face of said magnet in perpendicular relationship to said magnetizing axis, one of said flux-conductive armatures is so bent and/or shaped as to define, two air-gap regions arranged on either side of said magnetizing axis, whereas two yoke ends parallel to said magnetizing axis are placed in said air-gap regions.