PURPOSE: To make the thickness of the ink layer of a regenerated ink sheet constant by constituting powder ink by mixing at least two or more kinds of powder inks having different volume mean particle sizes.

CONSTITUTION: When an ink sheet 3 wherein an ink layer 2 is provided on an insulating support 1 is moved and ink is transferred to a recording medium 7 by a thermal head 5 to form an image, the release part 8 and adhesion part 9 of the ink layer are formed on the ink sheet 3. When powder ink 11 is supplied in such a state that voltage is applied between an electrode 10 and a sleeve 12, the powder ink 11 brought into contact with the release part 8 receives the injection of charge because the release part 8 shows insulting properties to be bonded thereto by electrostatic force but the powder ink brought into contact with the adhesion part 9 and the insulating support is prevented from adhesion because said ink is a mixture of two or more kinds of powder inks having different volume mean particle sizes and the powder ink 11a bonded to the ink layer 2 is scraped off by the powder ink 11b and only the release part can be replenished with the powder ink.