To increase grasping action of a floor surface for setting, and to surely and stably set an apparatus by screwing a screw rod into an attaching screw hole disposed on a bottom surface part of the apparatus, fitting and mounting a seat disk on a lower end part of the screw rod, and fixing a non-slip member to the bottom surface side of the seat disk.

A synthetic resin-made non-slip member 5 is formed in a disk shape having almost the same diameter as a seat disk 4, and four crest-shaped protrusions 6 are formed at clearances of 90 degrees. Recessed parts are formed on an upper end part of a locking cylindrical part of the non-slip member 5 at constant clearances, and projection parts are formed at constant clearances. When the lock cylindrical part is fitted into an annular groove part, those projection parts and the recessed parts are engaged with each other, and thereby, rotation of the non-slip member 5 to the seat disk 4 is blocked. It is thus possible to fix the non-slip member 5 forcibly and having durability without weakening sticking force of a double-faced adhesive tape by twist rotation of the non-slip member 5.