Ferrule, optical connector, and method for manufacturing ferrule

Provided is a ferrule (100) in which fiber holes (20, 25) for insertion of a plurality of optical fibers are provided in a front end surface (100a), and a boot insertion hole (35) of a boot insertion part (30) for inserting a ferrule boot (102) through which optical fibers are inserted is provided in a rear end surface (100b), wherein the ferrule (100) comprises an internal space that communicates the fiber holes (20) and the boot insertion hole (35), an adhesive filling window (55) of an adhesive filling part (50) for filling the internal space with an adhesive is provided in one surface, the width of the ferrule (100) in the boot insertion part (30) is larger than the width of the ferrule body (10), the ratio of the width to the height of the ferrule (100) in the boot insertion part (30) is 5 or greater, and the wall thickness of the ferrule (100) on the periphery of the boot insertion hole (35) at the thinnest portion thereof is 0.32 mm or greater.