Fabrication methods are shown to produce slender and cylindrical tungsten shafts by electrochemical etching. The shape of microshatf formed by electrochemical etching is determined by the combination of two conflicting factors, i.e., initial shape and diffusion layer. We can obtain a desirable shaft profile by adjusting the thickness gradient of diffusion layer. The diameter of microshaft is controlled by mathematical model based on relation between process parameters and diameter.