Micro electrical discharge machining (μEDM) is one of the main micro engineering technologies used for manufacturing of tool inserts. Mainly μEDM milling is used, but due to long machining time required to remove bigger volumes, die-sinking μEDM could be a good alternative, but the electrode wear has to be under control to be able to perform accurate machining. In this paper, a new approach for die-sinking μEDM process modelling is examined. The main issue is to model the wear effect on electrodes geometries accurately and to keep under control the random factors such as contamination of the gap and material homogeneity.