A control device for a machine tool for operating the machine tool by a numerical control, NC, program or moving commands generated by a manual operation, comprising: an input section having switching means for switching between an NC program operation mode and a manual operation mode, coordinate system mode selecting means for selecting the coordinates system of feed axes or a feed control function, and moving command generating means for generating moving commands by a manual operation; a storage section for storing three dimensional graphics of a spindle side structure and a table side structure of the machine tool and three dimensional graphics of arrows indicating the moving direction of the feed axes; a display calculating section adapted to receive the three dimensional graphics of the spindle side structure and the table side structure from the storage section and adapted to calculate the orientations of the spindle side structure and the table side structure and the direction of an arrow relative to one of the spindle side structure and the table side structure to be moved depending on the coordinate system, or the feed control function, selected by the coordinate system mode selecting means and depending on a rotation of a view point for viewing the machine tool and a workpiece, when the switching means of the input section is switched to the manual operation mode; and a displaying section for displaying the three dimensional graphics of the structure and the arrow calculated by the display calculating section wherein the three dimensional graphics of the structures and the arrows displayed in the displaying section are three dimensional shapes. an input section having switching means for switching between an NC program operation mode and a manual operation mode, coordinate system mode selecting means for selecting the coordinates system of feed axes or a feed control function, and moving command generating means for generating moving commands by a manual operation; a storage section for storing three dimensional graphics of a spindle side structure and a table side structure of the machine tool and three dimensional graphics of arrows indicating the moving direction of the feed axes; a display calculating section adapted to receive the three dimensional graphics of the spindle side structure and the table side structure from the storage section and adapted to calculate the orientations of the spindle side structure and the table side structure and the direction of an arrow relative to one of the spindle side structure and the table side structure to be moved depending on the coordinate system, or the feed control function, selected by the coordinate system mode selecting means and depending on a rotation of a view point for viewing the machine tool and a workpiece, when the switching means of the input section is switched to the manual operation mode; and a displaying section for displaying the three dimensional graphics of the structure and the arrow calculated by the display calculating section wherein the three dimensional graphics of the structures and the arrows displayed in the displaying section are three dimensional shapes.