To surely prevent generation of vibration and lowering of holding force by providing hollow parts in which fluid is filled along the elevating and lowering directions of door glass on side wall parts and arranging a pressure control means capable of freely pressurizing the side wall parts in the vicinity of the side wall parts provided with the hollow parts, in a run channel.

Hollow parts 26, 27 are formed on at least one of side wall parts 24, 25 along the elevating and lowering directions of door glass, preferably, both of the side wall parts 24, 25, in a run channel 21. In the vicinity of a proper location of the side wall part 24 having the hollow part 26, a pressure control means 31 capable of freely pressurizing the side wall part 24 is arranged. In this constitution, the hollow parts 26, 27 on the side of tip parts are compressed and internal pressure of the hollow parts 26, 27 located on the side of a slidable contact part can be increased by pressing a press plate 36 on the side wall part 24. Thus, vibration can be prevented by increasing holding force of door glass by the run channel 21 when door glass at the time of a traveling is in a stoppage state.