Numerical control apparatus

A numerical control apparatus for controlling a machine tool, comprising:

• a first control unit configured to control the machine tool for machining;
• an image display device configured to display at least status of the machine tool and the first control unit;
• a second control unit configured to control the image display device;
• a first light-emitting portion;
• and,
• a second light-emitting portion, wherein
• when an anomaly occurs in the second control unit, making the second control unit unable to display the status of the machine tool and the first control unit on the image display device, the first light-emitting portion notifies the status of the machine tool or the first control unit by emission of light and the second light-emitting portion notifies by emission of light that an anomaly has occurred in the second control unit,
• the first control unit and the second control unit are configured to control, while the numerical control apparatus is being booted up, the first light-emitting portion and the second light-emitting portion, respectively, so as to notify operating status of the first control unit and the second control unit in a stepwise manner that is in association with progress of a startup process.