Ink tank, ink-jet recording apparatus and method of manufacturing ink tank

A method of manufacturing an ink tank for supplying ink to an ink jet type recording head, said ink tank comprising a case body having an ink chamber containing the ink, and a heat insulating layer provided around said ink chamber for insulating against external heat, and a lid covering up an open top of said case body to close said ink chamber, said ink chamber being parted by a partition wall into an absorbent chamber containing at least an ink absorbent, and a storage chamber storing the ink to be absorbed by said ink absorbent, wherein said partition wall has an interconnection slot near a bottom of said ink chamber, to interconnect said storage chamber with said absorbent chamber, and said lid has an ink injection hole for injecting the ink in said storage chamber, and an air introduction hole for introducing air into said absorbent chamber, said method comprising steps of:

• placing said ink absorbent in said absorbent chamber;
• injecting thereafter the ink in said absorbent chamber through said open top of said case body, to let said ink absorbent absorb the ink and fill said absorbent chamber with the ink;
• mounting thereafter said lid to said case body to close said ink chamber;
• injecting thereafter the ink in said storage chamber through said ink injection hole of said lid;
• stopping thereafter said ink injection hole with a stopper;
• and
• sticking thereafter a seal onto a top surface of said lid, to cover said ink injection hole and said air introduction hole.