Abstract: A friction bearing structure for the adjustable support of a ventilator window shaft employed in an access door of an automotive vehicle, which comprises a base block having a rigid tongue member and a support hole, and a movable tongue member cooperative with the rigid tongue member. The rigid and movable tongue members have their respective surface area so shaped as to tightly contact the ventilator window shaft under friction so that, once the ventilator window is rotated to any desired position from a closed position, the ventilator window can be retained in position at such desired position. The structure further comprises a wedge member having a mounting hole through which an adjustment screw member loosely extend, and a pressure backing member for backing up a pressure exerted by the wedge member when the latter is held in position with the adjustment screw member being fastened into the support hole so that the pressure can be directed towards the movable tongue member.