Provided is an endoscope sheath including an elongated body having flexibility, the body having a first lumen through which an endoscope passes in a longitudinal direction of the body and a second lumen through which a guide wire passes in the longitudinal direction. A direction in which the second lumen opens at the distal end of the body gradually diverges from a direction in which the first lumen opens at the distal end, in a forward direction from the distal end.