At selection of the most appropriate machining process for a given part geometry technological process models are powerful and widely used tool. At best, technological process modelling reduces the number of process variables or at least defines the possibility of their aggregation and identifies their interdependencies. In this paper approach to technological modeling of micro electrical discharge milling (micro EDM milling) for grooved structures is presented. Overall machining time is modelled via experimentally determined interdependencies of process parameters. The technological model is confined to grooves narrower than 0.12 mm and shallower then 0.1 mm, thus structures which are commonly present in grooved micromixer designs. The presented model enables easier comparison of the micro EDM milling performance with other competitive technologies such as laser micromachining and micromilling.