A liquid supply device includes a liquid cartridge, which has a liquid chamber that stores liquid, a cartridge mounting portion, and a surface detector. The liquid chamber has a first portion, a second portion, and a third portion. The liquid cartridge removably attaches to the cartridge mounting portion. The surface detector detects a surface of the liquid stored in the liquid chamber. A horizontal cross-sectional area of the first portion of the liquid chamber is less than each of a horizontal cross-sectional area of the second portion and the third portion of the liquid chamber, and the first portion of the liquid chamber is positioned between the second portion and the third portion of the liquid chamber in a direction orthogonal to the horizontal cross-sectional area of the first portion of the liquid chamber.