A straw (3) capable of being detachably inserted into the straw insert hole (2) of a press-deformable container (1) having the straw insert hole (2), characterized by comprising a locking part (4) for stopping the insertion of the straw (3) into the straw insert hole (2) and a through hole (5) positioned apart from the locking part (4) by a distance (W) almost the same as the thickness of a container forming material having the straw insert hole (2).