A humidifying apparatus comprising a base comprising a chamber, a water tank removably mounted on the base for supplying water to the chamber, an impeller and a motor for driving the impeller to generate an air flow, an inlet duct for conveying the air flow to the chamber, humidifying means for humidifying the air flow with water from the chamber, and an outlet duct for conveying the humidified air flow from the chamber, wherein a lower surface of the water tank, which in use supports the water tank on the base, comprises a recessed portion for receiving water overflow from the chamber.