Liquid container having reinforcing member

A liquid container connectable to an ink jet recording head for an ink jet recording apparatus, said liquid container comprising a first chamber containing negative pressure producing material and having an outlet arranged, in use, at a lower part of the liquid container and connectable to the ink jet head to supply liquid from the liquid container to the ink jet head and an air vent for allowing ambient air into the first chamber, a second chamber, having plural walls, one of which partitions said second chamber from said first chamber, said second chamber communicating with the first chamber through a communication part disposed, in use, at the lower part of the liquid container and providing a liquid reservoir for the first chamber, the communication part including a first gap that separates a lower one of the plural walls from a lower portion of the wall partitioning said first and second chambers, the second chamber having deformation inhibiting means for preventing or at least inhibiting deformation of the second chamber that otherwise would be caused by gripping of the second chamber, wherein said deformation inhibiting means and the lower wall are separated by a second gap that is a free gap and is larger than the first gap.