A control device of an internal combustion engine which determines a target throttle opening degree in accordance with a required intake pipe internal pressure and which suppresses the occurrence of hunting of the throttle opening degree is provided, wherein, when the required intake pipe internal pressure becomes a predetermined pressure or more, the target throttle opening degree is determined by adding an addition-corrected throttle opening degree calculated in accordance with a difference between the required intake pipe internal pressure and the predetermined pressure based on a predetermined equation to an opening degree of a throttle valve making the intake pipe internal pressure the predetermined pressure.