PURPOSE: To provide a method of setting the origin of the spindles of a machine tool automatically and a device using this method.

CONSTITUTION: A cylinder body 7 is placed on the machining face of a machine tool 1, and detecting bodies 11a, 11b are provided at the lover ends of spindles 10a, 10b. The cylinder body 7 and the spindles 10a, 10b are brought into contact to obtain the center point coordinate of the cylinder body 7. This point is stored as the common origin of the spindles 10a, 10b into a storage means, and cutting is performed on the basis of this point.