To provide a stopper capable of holding a bathtub lid rolled up or folded standing at a corner.

The stopper 1 has an L-shaped arm 2 the middle section of which curves along the peripheral surface of the rolled up bathtub lid, and both ends of which are provided with the function of fast sticking to wall faces. The stopper 1 is attached to the wall face at the corner in a bathtub with both the ends of the arm 2 fast stuck. When the bathtub lid is stored, the lid is inserted inside the stopper in a rolled shape. A method for bringing the stopper 1 into fast sticking to the wall face has several ways where a flange section comprises a self-adhesive tape or suction cups, or fixture with screws. Fast sticking sections have a flexible structure so that properties for fast sticking to the walls are improved. Besides, the length of the arm is allowed to be adjustable.