To provide controller and control method for internal combustion engine that can suppress motor built in actuator from overheating when waste gate valve is controlled to near fully closed position or fully opened position, and can suppress from causing deterioration of fuel efficiency by consuming large power wastefully even in light load operation region in which pressure of exhaust gas is low relatively. A controller for internal combustion engine calculates basic operating amount for bringing real opening degree close to target opening degree; calculates an operating amount obtained by performing upper limitation of basic operating amount by first limit value, as final operating amount, in case of supercharging driving state; and calculates an operating amount obtained by performing upper limitation of basic operating amount by second limit value smaller than first limit value, as final operating amount, in case of non-supercharging driving state.