Abstract: A milling-boring machine is described which allows various types of operations to be carried out on a workpiece of medium-large size so as to allow its complete working in a single location. The machine includes a pillar, a slide movable vertically along the pillar and a cylindrical head rotatably mounted in the slide, the head being rotatable and the slide being movable by digitally controlled drive means. The head carries two mandrels with their axes parallel to each other and parallel to the axis of the head, and at a predetermined distance therefrom, the mandrels being selectively rotatable at different speeds. Selected tools are mounted on the mandrels and on tool accessories attachable to the head. The machine further includes an accessory magazine for selectively supplying accessories to the head and a tool magazine for selectively supplying tools to the mandrels and to the tool accessories, with automatic devices for changing the accessories and the tools.