A control device for an internal combustion engine with a turbo-supercharger including a variable valve mechanism at least at either one of an intake side and an exhaust side includes a scavenging amount setting means for determining an upper limit value of a scavenging amount moving from an intake passage to an exhaust passage across the interior of a cylinder during a valve overlap period to satisfy a performance requirement for the internal combustion engine, and a variable valve control means for controlling the duration of the valve overlap period according to the scavenging amount.