An electronic control unit (40) for controlling an internal combustion engine drive executes a first operation mode for injecting a fuel in a suction stroke while making an air/fuel ratio feedback control, when a demand for improving output characteristics is made in a medium/high load drive state of the engine. In response to a demand for raising the temperature of a catalyst, moreover, the first operation mode is switched to a second operation mode in which the fuel is injected in a compression stroke while making an air/fuel ratio feedback control performing a predetermined air/fuel ratio in the vicinity of a stoichiometric air/fuel ratio as a target value. At the time of switching to each of these operation modes, moreover, the air/fuel ratio correction coefficient of the air/fuel ratio feedback is increased/decreased to promote a shift of the output turning point of an O2 sensor (22) thereby to prevent such an instability of the air/fuel ratio control as is caused by the shift of the target air/fuel ratio accompanied with the switching to each operation mode. As a result, the temperature of an exhaust purifying catalyst (3) is raised in the second operation mode for performing the compression stroke injection stably in the vicinity of the stoichiometric air/fuel ratio, so that the exhaust cleaning performance can be improved and so that the output characteristics can be improved by executing the first operation mode.