Cylinder rest internal combustion engine

To provide a cylinder rest internal combustion engine capable of eliminating the steps in output in the case where the number of operative cylinders is changed. In a cylinder rest internal combustion engine including a plurality of cylinders divided into two or more groups, at least some of the cylinders being restable, a throttle valve TH of each of the cylinders being operable independently on the basis of the group to which the cylinder belongs, and the number of resting cylinders being controlled according to grip opening, the throttle valve opening is different between the groups, except for the full opening time and the full closure time of the throttle valve TH, and an ECU 70 is provided for opening the throttle valve of the next cylinder group before the throttle valve opening of the former cylinder group reaches the full opening.