To constitute a whole machine in a small size and at a low cost, by stopping a bar in machining process, suppressing the vibration of a main spindle, processing a work with high accuracy, concurrently cutting the bar stock by the user of the rotation of the main shaft, and omitting an exclusive bar cutting device and an exclusive work feeding device.

A through hole 5a is formed at the center of a main spindle 5, and an automatic chuck 7 is installed on the tip of the main spindle 5. A long size of bar 6 is inserted in a guide pipe 15 from the rear side of the main spindle 5 by a bar stock feeding mechanism, and fed to the automatic chuck 7. A cutting tool 13 is built in the automatic chuck 7, while a machining tool and a grasping mechanism 9 are provided to the turret 8 of a tool rest. The cutting tool 13 rotates integrally with the main spindle 5 and cuts the bar 6, in the condition the grasping mechanism 9 holds the bar 6, and the automatic chuck 7 releases the bar 6. A work cut from the bar 6 is grasped by the chuck 7, and machined by the machining tool.