To prevent the breakage of an engaging hook and a lock device, to make storage (installation) easy, to enlarge general-purpose properties, and to make the mounting of a skin easy.

This removable set comprises a seat part 7 and a back rest part 8 situated on a lower frame 6 formed of a plate member; an engaging hook 40 connected to and disconnected from the engaging part of a car body situated on the front and the rear side of the lower frame 6; and a lock device 43, the removable seat removably mounted on a car body. In a removable seat 5 removably mounted on a car body, a folding support leg 9 consisting of a front support leg 10 and a rear support leg 11 is situated on the under surface of the rear side of the lower frame 6. When the folding support leg 9 is folded, the support leg is positioned above the engaging hook 40 and the lock device 43 and when it is in a using state, it is protruded to a position situated below the engaging hook 40 and the lock device 43.