A liquid supplying device includes a tank and a cartridge configured to be attached to the tank. The cartridge includes a first storage chamber. The tank includes a second storage chamber, a liquid passage, a gas passage, and an air communication portion. The liquid passage has a first end formed with a first opening, and a second end formed with a second opening. The gas passage has a third end formed with a third opening, and a fourth end formed with a fourth opening. In an attachment state where the first storage chamber is in communication with both the second opening and the fourth opening, the first storage chamber has a portion positioned above the liquid passage and the gas passage, and the second storage chamber is positioned below the liquid passage and the gas passage.