This paper reports on batch mode die-sinking micro-EDM using Deep Reactive Ion Etched (DRIE) tungsten tool electrode, which is capable of producing arbitrary features of micrometer scale in stainless steels as well as other metals. The photolithography defined bulk tungsten substrates are etched by inductively coupled plasma (ICP) deep etching, with an etching depth over 200µm at an etch rate of 2.2µm/min. The high-aspect-ratio bulk tungsten structure is then used as EDM tool electrode, which is superior to state-of-the-art electrodes for its excellent wear resistance. The influences of the micro-EDM parameters on roughness, discharge gap, tool wear and profile are discussed along with the optimization. A feature size below 10µm with an aspect ratio up to 6 is demonstrated on the stainless steel workpiece; the roughness (Ra) of the micromachined surface is less than 100nm with an ultralow tool wear ratio of 17%, which are among the best of present reports.