Abstract: To prevent an optical fiber from readily detaching and to prevent the optical fiber from being damaged when a mechanical splice is used. A housing (2) has supply holes (58b, 59b) for supplying a bonding agent to both end parts of a metal sleeve (10). When the bonding agent is supplied through the supply holes (58b, 59b), the bonding agent enters the space between the outer circumferential surfaces of optical fiber strands and the inner circumferential surface of the metal sleeve (10), and the optical fibers can therefore be bonded to both end parts of the metal sleeve (10). Damage to the optical fiber strands can therefore be prevented even when the mechanical splice is used in an environment subject to frequent vibration. Water and debris can be prevented from entering through the apertures on the ends of the metal sleeve (10).