This research aims to develop a simulation method for die-sinking EDM to solve the inverse problem, in which the tool electrode shape to achieve the final shape of the workpiece is questioned. In this inverse simulation, the same algorithm as used in the forward simulation is adopted assuming that the initial shapes of the workpiece and tool electrode are equal to their shapes at the goal of the forward process. Moreover, the workpiece is fed in the opposite direction toward the tool electrode, and the data concerning the removal volumes per pulse discharge pertaining to the tool electrode and workpiece, respectively, are reversed. The algorithm is a simple repetition of the procedure which is comprised of: 1) determining the next discharge location, 2) removing the tool and workpiece electrodes, 3) distributing the debris particles, and 4) feeding the tool electrode. The simulation takes into account a variety of influential factors such as tool electrode wear, gap width distribution, curvature and inclination of the tool electrode, and debris particle concentation, all of which affect each other in a very complex manner. As a result of the inverse simulation, the shapes of the tool electrode and workpiece were restored to the initial shapes in the forward simulation.