A machine tool having an onboard measuring device automatically carries out various works which include ultra precision machining, washing and onboard measuring, by a numerical controller, without any interposition of a worker. For achieving this, an operation region of drive axes of the machine tool is previously divided into a machining region, a washing region and a measuring region. Positions of the drive axes are always monitored by the numerical controller, and when the drive axes enter each of the regions, a work allocated to each of the regions is automatically started and the work is continuously carried out until drives axes exit the region.