To provide an automatic lathe can be performed quickly and easily switch between when performing the processing of the material without using the case of using a guide bush for machining materials. And a headstock 6 and the guide bush support table 1, the motor 8 of the spindle drive is provided on the headstock 6, the guide bush rotation motor 11 provided in the guide bush support table 1, positioning the guide bush support table 1 a support base fixing means 15 for fixing Te, is regulated so as not to rotate freely and move forward and backward in the guide bush support table 1, a guide member 12 having a through hole main shaft 3 is inserted is formed, the distal end of the guide member 12 a guide bush 4 which is attached to the removable standing on, when removing the guide bush 4 from the guide member 12, a spindle locking means 37 for positioning and fixing the spindle 3 relative to the guide bush support table 1 at a predetermined position the provided.