The main body part is a substantially cuboid member in which an optical fiber is disposed. One width-direction side of the main body part is provided with a lid part capable of opening and closing with respect to the main body part on a hinge. An installation part on which an optical fiber or the like is disposed is formed on the upper surface (the surface facing the lid part) of the main body part. The installation part comprises a reference surface and a recessed portion that is formed closer to the distal-end side than is the reference surface and that is formed at a lower position than is the reference surface. The reference surface is a region where the optical fiber or the like is pressed down by a pressing part. The recessed portion is a region where a drop cable is pressed in by a pressing part.