A holder for holding optical fibers has pin inserting holes to which corresponding positioning pins are pierced from one end to another. An optical fiber fixing plate has fixing holes corresponding to the optical fibers and pin inserting holes corresponding to the positioning pins. On an equipping surface of the fixing plate is formed a reinforcement layer having piercing holes corresponding to the fixing holes and pin piercing holes corresponding to the pin inserting holes. Each optical fiber is fixed and adhered by inserting to each fixing hole while the pins are inserted to the pin inserting holes of the holder, pin piercing holes of the reinforcement layer and the pin inserting holes of the fixing plate. A front surface of the fixing plate is planarized by polishing the surface. Positions of the optical fibers are easily defined at an end surface of the optical fiber holder with high precision.