Ferrule for optical fiber and optical connector using this

A ferrule capable of preventing from injuring the fiber and forming tiny cracks inside when inserting the fiber in the ferrule, and small in manufacturing cost is presented. A ferrule 1 comprising a ceramic-made cylindrical main body 1b and a metal- or plastic-made back body 1a, wherein a penetration hole 21 formed in the axial direction of the back body 1b is a stepped hole having a larger hole 25 and a smaller hole 23, without step difference in the boundary of a taper hole 24 and smaller hole 23 at the back body 1a side, and the brim of the penetration hole formed in the rear end surface of the cylindrical main body 1b has a curved surface with a radius of curvature R of 0.2 to 0.5 mm.