To improve fuel economy and clean up exhaust gas satisfactorily while securing responsiveness during transition.

An airflow sensor 3, a throttle valve 4, an exhaust gas turbocharger 5, an intercooler 6, an electric supercharger 8 and an air intake pressure sensor 9 are arranged sequentially from the upstream side to the downstream side in an air intake passage 2 of an actual engine. An identification model DM formed by combining a plurality of pieces of virtual equipment which are set to have characteristics the same as those of pieces of real equipment acting on an air intake condition, is configured as an engine control system. The identification model DM determines control values for the virtual equipment so that the actual engine is brought into a target air intake condition, regarding, for example, an engine speed and an accelerator opening as parameters, and outputs the control values to the actual equipment. A driving current of the electric supercharger 8 is included as one of the control values.