The feasibility of electrochemical drilling and milling on stainless steel are investigated using tungsten microelectrode with $10{mu}m$ in diameter. For the development of environmentally friendly and safe electrochemical process, citric acid solution is used as electrolyte. A few hundred nanoseconds duration pulses are applied between the microelectrode and work material for dissolution localization. Tool fracture by Joule heating, micro welding, capillary phenomenon, tool wandering by the generated bubbles are observed and their effects on micro ECM are discussed. Occasionally, complex textures including micro pitting corrosion marks appeared on the hole inner surface. Metal growth is also observed under the weak electric conditions and it hinders further dissolutions for workpiece penetration. By adjusting appropriate pulse and chemical conditions, micro holes of $37{mu}m$ in diameter with $100{mu}m$ in depth and 26Jim in diameter with $50{mu}m$ in depth are drilled on stainless steel 304. Also, micro grooves with $18{mu}m$ width and complex micro hand pattern are machined by electrochemical milling.