In a control of an internal combustion engine control apparatus, the control apparatus includes: a fuel tank that stores a fuel; a vaporized fuel tank that is connected to an intermediate portion of an intake passageway of an internal combustion engine and that stores a vaporized fuel that is formed by vaporization of the fuel; an in-tank fuel supply device that supplies the fuel from the fuel tank into the vaporized fuel tank; and a normally-closed vaporized fuel supply valve that opens and closes a connecting portion between the vaporized fuel tank and the intake passageway. The control apparatus estimates air/fuel ratio in the vaporized fuel tank, and produces the vaporized fuel in the vaporized fuel tank by driving the in-tank fuel supply device, with the vaporized fuel supply valve closed, until the estimated air/fuel ratio becomes substantially zero, during operation of the engine. At the time of starting the engine, the control apparatus supplies the vaporized fuel stored in the vaporized fuel tank into the intake passageway by opening the vaporized fuel supply valve.