PURPOSE: To obtain recordings of good quality by a method in which a highly viscous ink is heated to reduce its viscosity and flown onto a recording paper.

CONSTITUTION: A highly viscous ink of 10CP of more at room temperature in an ink container 1 is heated by a heater 3 to reduce its viscosity. Although the tip of the ink 2 of high viscosity is positioned before a liquid discharge port 4, the ink 5 of low viscosity due to receiving of heat energy moves into the discharge port 4 by a capillary phenomenon. When air flows in an air jet nozzle 6, negative pressure occurs in the end of the discharge port, and the ink 5 comes out of the port 4, is flown by air stream, and reaches the recording paper 7 for recording. The viscosity of the ink 5 is gradually increased during the period when it reaches the recording paper and then becomes a value high enough to avoid the blotting of printed pictures by capillary action.