A nozzle of a cleaner includes a nozzle body, a rotation cleaning part having a rotation plate to which a rag is attached, a driving device provided in the nozzle body, a water tank, a water supply passage, and a water adjuster of which at least a portion is mounted on the nozzle body at a rear side thereof so as to be exposed to a rear surface or a top surface of the nozzle body. A user standing on the same floor surface as the nozzle body may manipulate the water adjuster by using his or her foot. The water adjuster may be configured to adjust an on/off operation and a rotation speed (e.g., rpm) of the pump motor.