Fuel injection control apparatus and method for internal combustion engine

A clutch switch (56) and an electronic control unit (61) are provided in a vehicle (11) in which transfer of toque output from an engine (12) to a manual transmission (39) can be interrupted by disengaging a clutch (38), provided between the engine (12) and the manual transmission (39), based on an operation of a clutch pedal (42). When an action to reduce the speed of the engine (12) is made ("YES" in step 110), the electronic control unit (61) determines, in step 120, the state of the clutch (38) based on the result of detection obtained by the clutch switch (56). If it is determined that the clutch (38) is engaged, the electronic control unit (61) gradually reduces the amount of fuel injected, in step 140. If it is determined that the clutch (38) is disengaged, the electronic control unit (61) gradually reduces the amount of fuel injected at a rate higher than that used if it is determined that the clutch (38) is engaged, in step 130.