A liquid storage tank having a compartment for accommodating a negative pressure generating member consisting of a fiber material, having a liquid supplying portion and a connecting portion with the atmosphere; a liquid storing compartment for storing liquid to be supplied to the negative pressure generating member, and having a connecting portion with the compartment for accommodating the negative pressure generating member and forming an almost closed space and a separating wall separating the compartment for accommodating the negative pressure generating member from the compartment for storing liquid and forming the connecting portion and an air importing portion for importing air from the compartment for accommodating the negative pressure generating member to the compartment for accommodating the liquid, formed in the vicinity of the connecting portion. The liquid storage tank has structure to suppress an unnecessary collapse in the negative pressure generating member in the vicinity of the air importing portion, such as concave portions on a wall opposite the separating wall in the compartment for accommodating the negative pressure generating member.