When a rotating body is oriented at a default position due to the absence of a driving force, a first hook portion and a second hook portion are engaged with a fixed engagement portion and/or a movable engagement portion. When the rotating body is rotated from the default position by the driving force, the first hook portion is engaged with one of the fixed engagement portion and the movable engagement portion, and the second hook portion is engaged with the other of the fixed engagement portion and the movable engagement portion. A throttle valve device includes a pressing portion that presses the first hook portion and/or the second hook portion to apply a pressing force toward a center of a coil portion in a coil axial direction.