A control apparatus for an internal combustion engine is provided which works to control an electric motor to start the engine through a belt transmission system. The control apparatus restricts rotation of the electric motor so as to keep a speed of the electric motor below a speed at which the electric motor is capable of producing a maximum torque until a given period of time passes since the electric motor is actuated to start in the motor mode. This enables the electric motor to generate the maximum torque when it is required to crank the engine.