Connectors of single fiber have been developed as connectors in which connection and disconnection are made one fiber by one fiber and furthermore, special emphasis has been laid on the reproducibility of the operability of connecting and disconnecting, and characteristics in connecting and disconnecting. The manufacturing method of multifiber connectors is a method that depends on a high precision grinding technique. The most essential point, undoubtedly, in applying multifiber plastic connectors to single-mode fiber is to raise the accuracy of the dimension of the ferrules. The fiber is inserted in the center hole of the ceramic ferrule and fixed in position with an adhesive, and the ferrule is inserted and fixed in the stainless steel housing. Transfer splicing in the cable system on-site is not so frequently conducted as compared with intraoffice connection using ordinary connectors. Precision-made ceramic or metal balls are placed in a mold and fibers are placed between the balls.