To provide a ball for cleaning a piping inner wall allowing the disappearance of its form with the passage of time even the ball is discharged to the natural world, and to improve lightness and work efficiency.

The cleaning ball is for cleaning the inside of the piping, and is a fiber formed body maintaining a spherical shape and formed by thermobonding fibers via a binder component with a part or all of polylactic acid binder fibers melted or softened. It is favorable that the polylactic acid binder fiber is a core-sheath combination type fiber arranged with a poly DL lactic acid with a high melting point in a core and a poly DL lactic acid with a melting point lower than the poly DL lactic acid of a core in a sheath part.