A liquid discharging device is provided. The liquid discharging device includes a sub coolant tank that is held by a carriage and stores a coolant for cooling a discharge head; and a coolant replacement portion that includes a main coolant tank which can communicate with the sub coolant tank, and replaces the coolant in the sub coolant tank with a coolant in the main coolant tank when the main coolant tank communicates with the sub coolant tank. The sub coolant tank does not communicate with the main coolant tank when the carriage is disposed at a liquid discharge position, and the sub coolant tank communicates with the main coolant tank when the carriage is disposed at a liquid refill position.