A liquid container for a liquid jet recording apparatus includes a first chamber containing negative pressure producing material and having a liquid outlet. At a lower part of the cartridge and contactable to the liquid jet head, the liquid container supplies liquid from the cartridge to the liquid jet head. An air vent allows ambient air into the cartridge. A second chamber communicates with the first chamber by means of a communication part, except for which the second chamber is substantially hermetically sealed. The second chamber is disposed at the lower part of the cartridge and provides a liquid reservoir for the first chamber. Ambient air is introduced through an air path substantially free of negative pressure producing material, having an inlet in the first chamber separated from the air vent by the negative pressure producing material, and an outlet arranged to be lower than the inlet during use of the cartridge to enable air to be supplied to the second chamber through the negative pressure producing material and the air path as liquid is withdrawn from the liquid outlet.