A numerical control system for readily finding machining programs containing desired machining steps and displaying the programs at a display device. A storage device stores machining programs and an internal table. A setting/registering unit creates the machining programs interactively in accordance with commands entered by an operator through an input device such as a keyboard, and registers the machining programs in the storage device with internal codes corresponding to the machining steps affixed thereto. When a command to perform a search for a specific machining step is entered by the operator, a command input unit requests the operator to enter a search start program number, a search end program number, etc., through the input device. On receiving the entered start program number, etc., a searching unit searches the machining programs, stored in the storage device, for the specific machining step, and outputs search data, whereupon a display control unit displays the search data at the display device.