An abnormality sensing method of a pressure sensor of a liquid discharge device comprising: a liquid ejection head (22-i, i = 1,2,...); a liquid accumulating unit in which a liquid to be supplied to the liquid ejection head (22-i, i = 1,2,...) is accumulated; a supply path (32, 36, 54) that guides the liquid accumulated in the liquid accumulating unit to the liquid ejection head (22-i, i = 1,2,...); a supply pump that feeds the liquid to the liquid ejection head (22-i, i = 1, 2,...) from the liquid accumulating unit through the supply path (32, 36, 54); a damper that is provided on the supply path (32, 36, 54) and that has a liquid chamber and an air chamber sectioned via a flexible membrane; and a pressure sensor, the abnormality sensing method comprising: an atmosphere opening step of opening the air chamber to atmosphere; a pressure value acquiring step of acquiring a pressure value from the pressure sensor in a state where the air chamber is open to atmosphere; and an abnormality determining step of determining whether or not there is abnormality in the pressure sensor based on comparison between a hydraulic head pressure between the damper and the pressure sensor caused by a difference of height at which the pressure sensor is provided with respect to a height at which the damper is provided and the pressure value acquired in a state where the air chamber is open to atmosphere. a liquid ejection head (22-i, i = 1,2,...); a liquid accumulating unit in which a liquid to be supplied to the liquid ejection head (22-i, i = 1,2,...) is accumulated; a supply path (32, 36, 54) that guides the liquid accumulated in the liquid accumulating unit to the liquid ejection head (22-i, i = 1,2,...); a supply pump that feeds the liquid to the liquid ejection head (22-i, i = 1, 2,...) from the liquid accumulating unit through the supply path (32, 36, 54); a damper that is provided on the supply path (32, 36, 54) and that has a liquid chamber and an air chamber sectioned via a flexible membrane; and a pressure sensor, the abnormality sensing method comprising: an atmosphere opening step of opening the air chamber to atmosphere; a pressure value acquiring step of acquiring a pressure value from the pressure sensor in a state where the air chamber is open to atmosphere; and an abnormality determining step of determining whether or not there is abnormality in the pressure sensor based on comparison between a hydraulic head pressure between the damper and the pressure sensor caused by a difference of height at which the pressure sensor is provided with respect to a height at which the damper is provided and the pressure value acquired in a state where the air chamber is open to atmosphere. an atmosphere opening step of opening the air chamber to atmosphere; a pressure value acquiring step of acquiring a pressure value from the pressure sensor in a state where the air chamber is open to atmosphere; and an abnormality determining step of determining whether or not there is abnormality in the pressure sensor based on comparison between a hydraulic head pressure between the damper and the pressure sensor caused by a difference of height at which the pressure sensor is provided with respect to a height at which the damper is provided and the pressure value acquired in a state where the air chamber is open to atmosphere.