A sub-tank is pressurized by a pump, with head valves closed. Then, one of the head valves is opened to perform a first purge on a first head. After the one head valve is closed, a different one of the head valves is opened to perform a second purge on a second head different from the first head. After these purges, an open-to-atmosphere valve is opened, with the head valves closed, to decrease the pressures inside the heads which are increased by the purges. This allows a selective purge on only a head which requires a purge. As a result, the amount of ink forced out is suppressed during the pressurized purges. After the sub-tank is made open to the atmosphere, a depressurizing pump depressurizes the sub-tank to form ink menisci in the heads. This prevents air bubbles from being drawn into nozzles during the formation of the ink menisci in the nozzles after the purges.