Abstract: A method for machine measurement for an NC processing machine is provided. The processing machine has a machine head, for example, a fork head and an associated mechanical and electrical spindle changing interface for holding a motor spindle. A laser interferometer with a beam generator and a beam detector is also provided and at least one measurement optic which interacts with the laser interferometer, for example, in the form of a reflector, and laser interference measurements, which are directed at a measurement optic, in particular distance measurements, carried out for machine measurement. The laser interferometer has an interface which corresponds to the spindle changing interface, and the laser interferometer is substituted for the motor spindle via the spindle changing interface for machine measurement, and is aligned by means of the machine axes for the laser interference measurements.