PURPOSE: To shorten a relative movement distance between a tool and a work to reduce a required installation floor area by constituting at least one axis of a tool movement device and a work movement device co-axially.

CONSTITUTION: A rotation of a spindle 7 and movements in X1-, X2-, Y-, and Z-axis are controlled by a command from an NC device, and a work 13 is machined with a tool 8. In this case, control is made so that feeding directions in X1- and X2-axis are opposed to each other. Namely, when the X1-axis is fed in positive direction, the X2-axis is fed to negative direction; when the X1-axis is fed in negative direction, the X2 axis is fed to positive direction. Accordingly, a relative movement distance between a tool 8 and a work 13 may be half the machining length of the work 13 (where the diameter of the tool 8 is zero). Also a relative movement distance between the tool 8 and the work 13 becomes twice that obtained when each of them is moved independently.