A throttle device, including: a throttle valve (13) disposed in a plurality of intake passages (12) of a throttle body (11); a throttle shaft (14) supporting the throttle valve (13); a motor (15) for driving the throttle valve (13) to open and close through the throttle shaft (14); a rotation transmission mechanism (20) interposed between the motor (15) and the throttle shaft (14); and a position sensor to detect a displacement in the rotation transmission mechanism (20). The rotation transmission mechanism (20) is disposed at a position where the first and the second throttle bodies (11f, 11s) are adjacent, the motor (15) is disposed within an installation width Ws of either one of the first and the second throttle bodies (11f, 11s), and the throttle opening degree sensor (30) is disposed within an installation width Wt of the other one of the first and the second throttle bodies (11f, 11s).