In a throttle valve device for an internal combustion engine, a stepped portion (51) is formed on an outer peripheral surface of an inner ring (41) on a bore side (on an air intake passage side) in order to limit movement of a lip portion (55) of a first lip seal (44) on the bore side toward an inside of a rolling bearing (4). Thus, even if a high supercharging pressure above an atmospheric pressure acts on the first lip seal (44), deformation and curling of the lip portion (55) due to the supercharging pressure can be prevented. As a result, separation of a second lip seal (45) on a gear cover side (on an outside) from the rolling bearing (4) can be prevented.