Shroud, moving blade element, and rotary machine

A shroud (22) is provided with shroud main bodies (22) that are secured to the blade tip of a moving blade (18) which is to be attached so as to extend from a rotor main body in the radial direction, and that are disposed so as to be mutually adjacent in the circumferential direction. The shroud main bodies (22) comprise: circumferential direction end faces (27, 28) having abutting end faces that mutually abut at the adjacent shroud main bodies (22), and opposing faces (34) which continue from the abutting end faces and face one another at the adjacent shroud main bodies (22) via a clearance (32); and outer circumferential surfaces (24) having a projection (40) that is formed so as to extend along one of the opposing faces (34) and that projects outward in the radial direction.