PURPOSE: To provide a ferruble for an optical connector of ≤1 micron in the micro-core part by forming the iside wall of a fine hole to a specular surface condition and forming an extra thin transparent material film on the surface thereof.

CONSTITUTION: A ferrule 1 for an optical connector has a fine hole 2 stuck with a material 4 for forming a specular surface body. A transparent body 5 is coated on the surface of the material 4. The light transmitted in the core part is transmitted without attenuation. Powder, paint or fluid of a metal, ceramic, resin, etc. is usable for the material of the hole 2 as far as said material forms a specular surface. The material 5 is, for example, glass, resin, etc. The material 5 prevents the material 4 from being flawed.