Abstract
A throttle device includes a valve element, a valve shaft with the valve element fixed thereto, a motor for rotating the valve shaft, a housing in which the motor is accommodated, and a cavity for mounting the motor in the housing. The cavity includes a large-diameter accommodation section and a small-diameter accommodation section, which are arranged coaxially. The minimum thickness between the inner peripheral surface of the large-diameter accommodation section and the outer peripheral surface of the housing is equal to or thinner than the minimum thickness between the inner peripheral surface of the small-diameter accommodation section and the outer peripheral surface of the housing.