In a controller of an internal combustion engine equipped with an electric supercharger driven by a motor, an object is to attempt to improve fuel consumption of a vehicle.The controller includes an electric supercharger driven by a motor; a generator that performs power generation using the output of the internal combustion engine as power; a charging device which is charged by the generator and can store electricity; and an accelerator opening degree detector that detects an accelerator opening degree. In the controller, a configuration is made such that, the controller controls supply electricity to the electric supercharger and generated electricity by the generator by the output of the accelerator opening degree detector, output needed for the electric supercharger calculated depending on the accelerator opening degree, and an state of charge in the charging device.