To provide a control device for an internal combustion engine capable of surely suppressing vibration at a time of idling operation of the internal combustion engine including multiple cylinders.

Crank rotation speed is detected for each cylinder when each cylinder goes into expansion stroke. Average value of continuous eight engine rotation speeds at a time of expansion stroke of each cylinder going into expansion stroke is calculated. The calculated average value and crank rotation speed at a time of expansion stroke of each cylinder are compared, ignition timing of a spark plug 31 of a cylinder of which crank rotation speed at a time of expansion stroke is below the average speed is advanced and ignition timing of the spark plug 31 of the cylinder of which crank rotation speed at a time of expansion stroke is above the average speed is retarded. When ignition timing reaches MBT and crank rotation speed at a time of expansion stroke i of the cylinder is below the average speed, air fuel ratio of the cylinder is shifted to rich side.