Provided is technology of raising or lowering vehicle height even if the grasp of vehicle speed is disabled. A vehicle height adjusting device includes a rear suspension capable of changing relative positions of a vehicle body frame and a wheel of a motorcycle including a transmission configured by a plurality of gears and a control device configured to control the rear suspension and change the relative positions of the rear wheel and the vehicle body frame to adjust vehicle height, which is the height of the vehicle body frame. The control device controls the rear suspension to increase the vehicle height when a gear position of the transmission is equal to or higher than a predetermined gear position set in advance and reduce the vehicle height when the gear position is lower than the predetermined gear position.