To perform smooth ink supply and printing operation stably by preventing waste of time and ink.

A print head 20 is coupled with an ink tank 40 through an ink supply tube 31 and an ink return tube 33 so that ink can be fed from the ink tank 40 to the print head 20 by driving a feed pump 32 coupled with the ink supply tube 31 and ink can be returned from the print head 20 back to the ink tank 40 by driving a return pump 34. The ink supply tube 31 is provided with a heating means 50 on the downstream side of the feed pump 32. The ink temperature is detected in the ink supply tube 31 and/or the ink return tube 33 and the quantity of ink being fed to the feed pump 32 and the quantity of ink being returned back to the return pump 34 are controlled based on the ink temperature.