To prevent the floor from being hurt and to realize easy attachment by making a piercing hole that is through the main body of the bottom and the protecting part and shortens its diameter as it becomes closer to the upper top.

Side part 2 lessens its diameter as it comes closer to the upper top and has some elasticity. So the cap 1 steadily fits to the end of legs of furniture. Furthermore, the cap can be freely detached from or attached to the ends of the legs. Each of bottom part 31 and protecting part 32 have a piercing hole that corresponds each other and be piled so as to compose a piercing hole 34. When the cap 1 is pressed and fit to the end of the leg, as the air in the cap 1 will be freed out through the piercing hole 34, the air cannot be pressed in the cap 1. So it can be easy to fit and attach, and, deformation of the cap will also be prevented. It also prevents floors of floorings and the like from being hurt even if the furniture is slid along the surface of the floor.