To accurately reflect fuel in gas containing fuel to setting of fuel injection quantity to cope with quick change of valve timing and the like.

Quantity MPMANI of gas containing fuel in an intake manifold is calculated by balance calculation of quantity PURGEQ of gas containing fuel flowing in an intake air passage and quantity MPCYL of gas containing fuel flowing in a cylinder from an intake manifold. Ratio MPMRTIO of calculated MPMANI to total quantity MAMANI of gas in the intake manifold is calculated, and quantity MPCYL of gas containing fuel sucked in the cylinder is calculated by multiplying the calculated MPMRTIO and total quantity MACYL of gas flowing in the cylinder together. Fuel injection quantity is corrected based on the calculated MPCYL.