A flange is formed in a ferrule. A forceps stopper has a fixing member engaging with the flange and a stopper body that holds the fixing member. The fixing member has detachable first and second pieces. The stopper body has a fixing member accommodation hole that accommodates the fixing member in a combined state. The stopper body has a fixing member holding portion that holds the fixing member that is accommodated in the fixing member accommodation hole. The fixing member holding portion has an annular contact portion that comes into contact with the fixing member and a connection portion that connects the outer periphery of the annular contact portion to the opening peripheral edge portion of the fixing member accommodation hole. When the stopper body is pulled, the connection portion is broken, so that the holding of the fixing member using the fixing member holding portion is released.
