Cylinder intake-air quantity calculating apparatus and method for internal combustion engine

An apparatus for calculating a mass air quantity sucked into one of cylinders of an internal combustion engine, comprising:

• a cylinder sucked mass air quantity calculating section that calculates a mass air quantity sucked into a corresponding one of the cylinders of the engine on the basis of a mass air quantity within an intake manifold and a volume of the corresponding cylinder while performing income and outgo calculations between a mass air quantity flowing into the intake manifold and that flowing out from the intake manifold to calculate the mass air quantity within the intake manifold;
• and
• a correction section that corrects the mass air quantity within the intake manifold calculated as a result of the income and outgo calculations between the mass air quantities during a stop of the engine on the basis of a crank angular position during the stop of the engine to calculate finally the mass air quantity within the intake manifold during the stop of the engine.