[Problem] To improve the sliding movement of a long body such as a catheter even when the inner diameter of the distal portion of a sheath becomes gradually smaller toward the distal side. [Solution] A sheath (20) for an introducer, which is formed of a sheath tube (21) comprising a hollow portion (21a) through which a elongated body is freely insertable, and which comprises a sheath distal portion (50) and a sheath main body portion (60). The internal diameter (¦a) of the sheath distal portion of the sheath for the introducer becomes gradually smaller toward the distal side. At an inner surface (50a) of the sheath distal portion, the sheath for the introducer comprises a hydrophobic coating (71) which has a friction coefficient lower the a friction coefficient of the sheath tube.