To realize an ink pressure control corresponding to an environmental temperature change by controlling a temperature of an ink pressure unit.

A pressure adjustment spring 212 at an ink pressure adjustment unit 2 which adjusts an ink output pressure supplied to nozzles to compete with a pressing force of the pressure adjustment spring 212 is supported by a case which expands and shrinks in accordance with a temperature. A temperature control is applied to the ink pressure adjustment unit 2. The case expands in accordance with a temperature increase, thereby decreasing the pressing force of the pressure adjustment spring to lower the ink output pressure. A change in ink pressure supplied to the nozzles is thus restricted. The temperature control is carried out while comparing a temperature change with an ambient temperature when a reference ink pressure is set and an environment temperature.