Patent ID: 8070273

Claim:
An ink storage container comprising an ink storage unit that stores an ink, the ink storage unit including an air flow control unit that controls an amount of air flow between inside and outside of the ink storage unit, wherein the air flow control unit includes: a valve element that is formed of an interconnected porous material and allows air to be exchanged between the inside and outside of the ink storage unit according to positive and negative changes in internal pressure of the ink storage unit; and a liquid repellent membrane having air permeability and liquid repellency, the liquid repellent membrane being disposed on an ink side of the valve element; and the liquid repellent membrane has a plurality of fine pores of a diameter of 0.01 Î¼m or more and 5 Î¼m or less, and the liquid repellent membrane has a critical surface tension of 25 dyn/cm or less.