PURPOSE: To prevent the nozzle of an ink jet head equipped with an ink chamber and an air chamber from being clogged by causing a solvent to fill up the air chamber during recording is not carried out to prevent ink from sticking to the ink nozzle.

CONSTITUTION: At the time of recording, a piezoelectric element 10 is caused to bend to vary the capacity of an internal ink chamber 4 and ink droplets 9 are discharged from an ink nozzle 8 and they are flown to a recording paper 14 by an air current spouted from an air nozzle 13 formed in an air chamber 12 and recording is made by causing ink droplets 9 to adhere to the recording paper 14. At the time of interruption of recording, a 4-way valve is changed over and a solvent 26 in a solvent tank 23 is caused to fill up the air chamber 12 by pressurized air from an air supply source 15. When recording is resumed, the 4- way valve 17 is changed over to its original position again, and the solvent filled in the air chamber 12 is discharged by air from the air supply source 15.