A cleaning and drying-preventing method including: positioning a nozzle in a container such that a funnel-like inner circumferential surface of the container is located around a periphery of a distal end of the nozzle; sucking a liquid in the nozzle to retract a level of the liquid to a side of a supply passage; supplying a solvent into the container to form a swirl flow of the solvent turning around the distal end of the nozzle, and cleaning the nozzle by the swirl flow; supplying a solvent into the container to form a liquid pool of the solvent; and further retracting the level of the liquid in the nozzle to the side of the supply passage. A liquid layer, an air layer, and a solvent layer are formed in the nozzle in this order from the side of the supply passage, to prevent drying of the liquid in the nozzle.