Ink jet recorder and recording head cleaning method

An ink jet recorder comprising a subtank and an ink jet recording head mounted on a carriage moving in parallel with a platen, an ink cartridge being placed outside said carriage for communicating with said ink jet recording head by a tube, ink supply means for feeding ink from said ink cartridge into said recording head under pressure, capping means for sealing nozzle openings of said recording head outside a print area of said carriage, and a waste ink tank for storing waste ink from said recording head, characterized in that

• said ink jet recording head comprises two common ink chambers in communication with both sides of pressure generation chambers and ink supply ports where ink flows into said common ink chambers from a position outside of said ink jet recording head, one ink supply port being connected to said subtank and the other being connected to said ink cartridge, wherein said subtank is replenished with ink through said ink jet recording head by said ink supply means and ink is made to reversely flow into said ink cartridge via said recording head from said subtank for printing.