An internal combustion engine control apparatus including a microprocessor. The microprocessor is configured to perform determining whether a start of the internal combustion engine is complete, determining whether a warm-up of an exhaust catalyst device is needed, acquiring an information on a temperature inside a cylinder, switching an injection mode, and controlling the fuel injector to inject the fuel in accordance with the injection mode, the switching including switching the injection mode to the first injection mode when the start of the internal combustion engine is complete and the warm-up of the exhaust catalyst device is needed, and switching the injection mode to the second injection mode or the third injection mode in accordance with the information on the temperature when the start of the internal combustion engine is complete and the warm-up of the exhaust catalyst device is not needed.