PURPOSE: To enable the parallel arrangement of nozzles in high density and to make it possible to operate the titled printer at low voltage, by applying pulse like voltage to a pair of electrodes holding rod shaped conductive solid inks, each of which is arranged so as to be contacted with the inside of each nozzle at one end thereof, therebetween.

CONSTITUTION: Each solid ink 30 is always pressed to the inside of each nozzle 20 at one end part 30a by the extrusion arm 74 of a feed apparatus 70. When predetermined voltage is applied between electrodes 40 in a pulse form by a voltage generation circuit 50, a current is flowed through fine pieces 32 in one end part 30a of the solid ink 30 in a shortcircuited state. At this time, because the electrodes 40 and one end part 30a of the solid ink 30 are contacted so as to leave an extremely slight minute gap therebetween, even the ink main body part 31 such as wax is instantaneously melted by not only discharge due to the gap and the heat generation of the conductive fine pieces 32. By this mechanism, the liquified part is emitted from the nozzle 20 as ink droplets.