PURPOSE: To execute with a high accuracy and a high efficiency working of an optical fiber inserting hole by forming a ferrule body to the prescribed size and shape accuracy, and thereafter, installing it to a ferrule fixing jig aligned in advance, and piercing an optical fiber strand inserting hole in its center.
CONSTITUTION: A ferrule body whose outside diameter has been formed with a high accuracy is installed to a fixing jig 3, and an optical fiber strand inserting hole 6 is pierced from an end face 4 side of the ferrule body by a precise hole working machine 1. As for a forming material for forming the ferrule body, it is necessary that this material is a low contraction and low thermal expansion material, scarcely causes a size variation against humidity, chemicals, etc., and is excellent in mechanical characteristics such as corrosion resistance, bending strength, etc., in order that the outside periphery side and the shape accuracy are managed within a target accuracy. As for a concrete resin, an epoxy compound resin, a phenol compound resin, or an unsaturated polyester compound resin, etc. are exemplified. In this way, working of an optical fiber strand inserting hole can be executed with a high accuracy and a high efficiency, and an extra process can be omitted.