A device for imparting an orbital angular momentum to a charged particle wave propagating along a beam axis in a charged particle beam generating apparatus is described. The device comprises a support element having a target region adapted for transmitting a charged particle wave propagating along a beam axis and an induction means for inducing a magnetic flux along an elongated profile having a free end portion located in the target region and the induction means is adapted for providing a magnetic flux in the elongated profile in order to induce an angular gradient, relative to the beam axis, of the phase of the charged particle wave when transmitted through the target region. A corresponding method is also disclosed, as well as the use thereof in electron microscopy.