A front shoe as a sliding member includes a pair of support walls facing each other in a vehicle width direction, and a fulcrum shaft disposed in a bridging manner between both support walls. A support bracket as a support member supporting a movable panel and integrally moving while being joined to the front shoe includes a joint block having an engagement portion for the fulcrum shaft and serving as a second joint portion joined to a first joint portion on the front shoe side. Further, the joint block is arranged between both support walls while being relatively rotatable about the fulcrum shaft. On the joint block, a cushion member interposed between the joint block and the support walls while being fixed thereto is disposed.