A fuel injection control device for an internal combustion engine, the engine comprising a cylinder, an intake passage through which air is taken into the cylinder, an intake valve which blocks communication between the cylinder and the intake passage at a predetermined crank angle, an intake air amount regulating mechanism (23, 27) which regulates an intake air amount of the cylinder in accordance with an accelerator opening, the intake air amount regulating mechanism (23, 27) comprises an intake throttle provided in the intake passage, a sensor which detects a flow rate (Qa) of the intake passage upstream of the intake throttle, a predetermined response delay (T2, Tv2) existing between the accelerator opening and the intake air amount adjustment performed by the intake air amount regulating mechanism (23, 27), and a fuel injector which supplies the intake air with an amount of fuel corresponding to the intake air amount, the fuel injection control device comprising: a programmable controller programmed to: calculate a target intake air amount (Qc) on the basis of the accelerator opening, and control the regulating mechanism to realize the target intake air amount (Qc); calculate a throttle opening area conversion value (AAPO) from the accelerator opening; calculate an intake throttle opening area (ATVO) from a throttle opening of the intake throttle; calculate an accelerator opening cylinder intake air amount (Qca, Qcff) as a function of an elapsed time (t) from a change in the accelerator opening, from a ratio (AAPO/ATVO) between the throttle opening area conversion value (AAPO) and the intake throttle opening area (ATVO), and the flow rate (Qa) in the intake passage; specify the elapsed time (t) corresponding to a second delay period which is determined from the predetermined response delay and a time period extending from the fuel injection timing to a closing of the intake valve; calculate a required injection amount corresponding to the fuel injection timing of the fuel injector on the basis of the accelerator opening cylinder intake air amount (Qca, Qcff) and the specified elapsed time (t); calculate the target fuel injection amount (Ti) from the required injection amount; and control the fuel injector to inject a fuel in the target fuel injection amount (Ti) at a predetermined injection timing. a programmable controller programmed to: calculate a target intake air amount (Qc) on the basis of the accelerator opening, and control the regulating mechanism to realize the target intake air amount (Qc); calculate a throttle opening area conversion value (AAPO) from the accelerator opening; calculate an intake throttle opening area (ATVO) from a throttle opening of the intake throttle; calculate an accelerator opening cylinder intake air amount (Qca, Qcff) as a function of an elapsed time (t) from a change in the accelerator opening, from a ratio (AAPO/ATVO) between the throttle opening area conversion value (AAPO) and the intake throttle opening area (ATVO), and the flow rate (Qa) in the intake passage; specify the elapsed time (t) corresponding to a second delay period which is determined from the predetermined response delay and a time period extending from the fuel injection timing to a closing of the intake valve; calculate a required injection amount corresponding to the fuel injection timing of the fuel injector on the basis of the accelerator opening cylinder intake air amount (Qca, Qcff) and the specified elapsed time (t); calculate the target fuel injection amount (Ti) from the required injection amount; and control the fuel injector to inject a fuel in the target fuel injection amount (Ti) at a predetermined injection timing. calculate a target intake air amount (Qc) on the basis of the accelerator opening, and control the regulating mechanism to realize the target intake air amount (Qc); calculate a throttle opening area conversion value (AAPO) from the accelerator opening; calculate an intake throttle opening area (ATVO) from a throttle opening of the intake throttle; calculate an accelerator opening cylinder intake air amount (Qca, Qcff) as a function of an elapsed time (t) from a change in the accelerator opening, from a ratio (AAPO/ATVO) between the throttle opening area conversion value (AAPO) and the intake throttle opening area (ATVO), and the flow rate (Qa) in the intake passage; specify the elapsed time (t) corresponding to a second delay period which is determined from the predetermined response delay and a time period extending from the fuel injection timing to a closing of the intake valve; calculate a required injection amount corresponding to the fuel injection timing of the fuel injector on the basis of the accelerator opening cylinder intake air amount (Qca, Qcff) and the specified elapsed time (t); calculate the target fuel injection amount (Ti) from the required injection amount; and control the fuel injector to inject a fuel in the target fuel injection amount (Ti) at a predetermined injection timing.