Abstract: In an electron microscope employing a multi-element electrostatic lens and a position adjustable electron emission gun, the gun tip must be in precise alignment with the very small apertures in the lens elements for high resolution imaging. If the tip is precisely aligned, there will be no variations in displacement of an image if the lens element potentials are varied; if there is misalignment, the image displacement will vary with voltage variations. Thus, proper alignment of the gun tip is easily and rapidly achieved by varying the lens element potential with an oscillator while adjusting the position of the gun tip to a zero image variation.