The object of the present invention is to provide an internal combustion engine control apparatus which can control an internal combustion engine output with a high accuracy even when an internal combThe object of the present invention is to provide an internal combustion engine control apparatus which can control an internal combustion engine output with a high accuracy even when an internal combustion engine output lower than an unloaded idling equivalent output is demanded. The internal combustion engine of the present invention has an accessory such as a generator driven through an outputustion engine output lower than an unloaded idling equivalent output is demanded. The internal combustion engine of the present invention has an accessory such as a generator driven through an outputaxis of the engine, an ECU for totally controlling the engine and accessory, and an accessory driving control section for controlling the driving of the accessory. The ECU calculates a target engine oaxis of the engine, an ECU for totally controlling the engine and accessory, and an accessory driving control section for controlling the driving of the accessory. The ECU calculates a target engine output according to a demand from a driver or the like and, when the target engine output is lower than the unloaded idling equivalent output, sends a control signal to the accessory driving control seutput according to a demand from a driver or the like and, when the target engine output is lower than the unloaded idling equivalent output, sends a control signal to the accessory driving control section 16 so as to increase the load of the accessory and further make the idle-up amount zero. When the target engine output is not lower than the unloaded idling equivalent output, an idle-up amountction 16 so as to increase the load of the accessory and further make the idle-up amount zero. When the target engine output is not lower than the unloaded idling equivalent output, an idle-up amountcorresponding to the load of the accessory is determined. Then, the idle-up amount of output is added to the target engine output, and the engine device is controlled according to thus calculated valucorresponding to the load of the accessory is determined. Then, the idle-up amount of output is added to the target engine output, and the engine device is controlled according to thus calculated value.e.