A prototype microelectrodischarge machine (micro-EDM) with a piezoactuated tool feed mechanism has been developed. In micro-EDM, the tool also experiences continuous wear during machining. This necessitates a tool wear compensation technique to attain a specified depth of micromachining on the workpieces. Tool wear compensation studies are performed during micromachining of silicon wafers using a copper tool. In order to estimate the necessary tool wear compensation, an axial tool wear and micromachined hole-depth measurement technique is incorporated, and variation in wear ratio at different depths of micromachining is investigated. Process simulation of micro-EDM is also performed to estimate the tool wear compensation required to reach a predefined depth during micromachining on silicon. Results obtained by simulation for the required tool feed, depth of hole achieved corresponding to a set value, and the resulting axial tool wear are in close agreement with experimental results. A machining depth variation of about 6% with respect to the estimated depth is observed. This approach provides a process control methodology for mircromachining of semiconductor and conducting materials to predefined depth with high accuracy.