The present invention relates to a cleaner. In one aspect, the cleaner includes a nozzle assembly; a cleaner body connected to the nozzle assembly; and a water tank to which a cloth is attached, wherein the water tank is coupled to the nozzle assembly and is configured to supply water to the cloth.The water tank comprises: a water storage unit to store water and having a water inlet; a water flow adjuster configured to close or open the water inlet and to adjust a water flow amount from the water storage unit to the cloth when closing the water inlet; and a stopper formed on the water storage unit to limit a rotation of the water flow adjuster, wherein the water flow adjuster has a receiving groove to receive the stopper therein, wherein the receiving groove includes a delimitation portion to limit a rotation of the water flow adjuster in a first direction and having a tilted surface to allow the stopper to be exited out of the receiving groove.