A liquid discharge device includes a casing, a carriage, a discharge head, a sub tank, an energy supply device, and a controller. The casing has a space for housing a main tank. The carriage is capable of moving. The discharge head is arranged on the carriage. The sub tank is arranged on the carriage. The sub tank communicates with the discharge head. The sub tank is connected with the main tank when the carriage is located at a predetermined position. The sub tank is disconnected with the main tank when the carriage is located at positions other than the predetermined position. The energy supply device supplies energy to liquid within the main tank such that the liquid within the main tank is discharged. The controller controls the energy supply device such that the ink within the main tank is supplied to the sub tank when the carriage is located at the predetermined position. The controller controls the energy supply device such that the liquid within the main tank is discharged before the carriage arrives at the predetermined position.