Abstract: A numerical control apparatus enables a tool to move parallel or vertical to a designated shape to easily carry out a machining of a prototype using general-purpose machine tools. A graphic storing device displays guidance information on a display unit through a graphic control circuit and also stores a designated shape such as an oblique straight line or a circular arc entered by the operator through a keyboard in an interactive fashion. On the detection of a pulse signal HP from a manual pulse generator, an interpolation device reads a changeover signal H/V for commanding one of the parallel movement or the vertical movement of the tool from a changeover device. Then, the interpolation device outputs an interpolated pulse signal CP corresponding to the pulse signal HP and changeover signal H/V in accordance with the designated shape stored in the graphic storing device and supplies the interpolated pulse signal HP to an axis control circuit.