A tool-main-spindle, whose cutting angle can be changed, is translated by an X-axis moving mechanism portion on an X-axis provided in a plane perpendicular to an axis of a work, and is translated on a Y-axis by a Y-axis moving mechanism portion. Cutting of the work is performed by setting the cutting angle of the tool-main-spindle to an angle of the cutting tool at which the work has large dynamic rigidity, and causing an axis of a cutting tool to cross the work axis, and cutting the work with the cutting tool toward the axis of the work by cooperatively operating the X-axis moving mechanism portion and the Y-axis moving mechanism portion.

The machine tool 1 for machining a hole 3a of a desired size in a workpiece 3, includes: a main shaft 30 holding a tool 2; a spindle unit 40 including a spindle 41 which holds the shaft 30 rotatably on the axis r of rotation, and a housing 42 which covers the periphery of the spindle 41; a drive unit 50 for holding the unit 40 tiltably with respect to the workpiece 3 held by a holder 20, and for moving the unit 40 relative to the workpiece 3; a mount 70 extending from the housing 42 toward the periphery of the shaft 30; and a control section 90 which, based on the results of measurement by distance measurement sensors 82 held by the mount 70, controls the unit 50 so as to correct the inclination of the shaft 30 with respect to the workpiece 3.

A method for measuring a rotation center of a multi-axis processing machine 100 includes: using reference ball 8 and a measurement device 7 which has a probe 71 and measures, as a measurement value 72, a movement amount of the probe 71 when the reference ball 8 contacts the probe 71; executing a measurement process of rotating the rotation axis to measure the measurement value 72 in a state in which the reference ball 8 installed to one of the processing head 2 and the table 62, 63 contacts the probe 71 of the measurement device 71 installed to another of the processing head 2 and the table 62, 63; and executing a rotation center calculation process of calculating a rotation center of the rotation axis from the measurement value 72, a rotation angle of the rotation axis, and a position of a center of the reference ball 8.