A drain hose 1 includes a drain hose body 10 and a hard member 20. The hard member 20 includes a notch 22 and hooks 21. The drain hose body 10 includes a protruding portion 14 provided to a part, of an outer periphery of the drain hose body 10, to which the hard member 20 is attached. The protruding portion 14 protrudes to be positioned in the notch 22, and, when force is applied to the drain hose body 10 in a direction to pull the drain hose body 10 from a through hole P1, depresses edge portions 22a of the notch 22 in a direction to expand the hard member 20 in diameter.