A manufacturing method of a power MOSFET employs a hard mask film over a portion of the wafer surface as a polishing stopper, between two successive polishing steps. The method uses a device for internal centrifugation of mineral fibers including a centrifuge equipped with a peripheral band perforated with orifices distributed in a plurality of annular zones arranged on top of each other, assuming that the centrifuge is in centrifugation position. Each market table includes rule identifiers corresponding to at least one connection path, and each rule table is associated with a rule identifier corresponding to one of the rule identifiers contained within a respective market table. Thus, an operator of the control system 10 can carry out the work of tracing the cause of the trouble of a machine tool 70 and of examining efficient machining processes of the machine tool 70 by simultaneously watching the control data displayed on one display unit 80. The heat pipe contacts the casing. Individual context associations may contain a smaller subset of data corresponding to a specific relationship association.