In a stand-by state, when an instruction unit issues the printing instruction, a control unit is switched in a maintenance state, in the maintenance state, the control unit closes an air valve and operates a first pump, and when a sensor detects that the ink of a second tank is reduced by discharging the ink from a nozzle by the pressure of a second tank, the control unit opens the air valve to be switched in a printing state, and when a predetermined time elapses after an operation of the first pump before the sensor detects the reduction of the ink of the second tank, the control unit excludes the solidified ink from the nozzle, and in the printing state, the control unit is switched in the stand-by state when the ink is discharged from the nozzle of the head based on a printing instruction.