To prevent a catch ring from giving damages to a door or generating noise by a method wherein a fixing groove for fixing the catch ring to be hooked on to a hooking part is formed to a main body for supporting a contacting part that comes into contact with the door.

A main body 4 is constructed of a contacting part 1 made of synthetic rubber or the like, a catch ring 2, a swing body 5 with a fixing groove 3 formed thereto, and a base 6. The fixing groove 3 is formed on a position slightly parting from a position whereto the catch ring 2 is returned and on a position whereon the catch ring 2, with its diameter slightly enlarged, can cross over its edges. The catch ring 2 is not brought inadvertently to a position between a door and the contacting part until it is operated by fingers for keeping the door open, being prevented from hitting the door and causing damages and generating much noise.