A robot cleaner is disclosed, which comprises a main body forming an external appearance, a water bucket unit provided in the main body, supplying water to a water mop, a driving wheel rotated by a rotational force of a driving motor provided in the main body, moving the main body, and a wiper module provided in the water bucket unit, wherein the wiper module is extended to front and rear directions of the driving wheel and formed to be protruded toward the floor where the main body drives.