Ink tank

An ink tank comprising a negative pressure generating member for retaining ink, a case for accommodating said negative pressure generating member, said case having an atmospheric opening for communicating atmosphere with an inside of said case, said case further including an ink supply portion through which the ink is led out to an exterior area, and an ink holding member having a substantially columnar shape in the ink supply portion and developing a higher capillary action than that of said negative pressure generating member, wherein:

• said case includes a supply-side wall, in which the ink supply portion is disposed, and a pair of oppositely-faced side walls adjacent the supply-side wall, with inner surfaces of said pair of oppositely-faced side walls having a flat portion adjacent said ink supply portion;
• a recess is formed in the flat portion of the inner surface of each of said pair of oppositely-faced side walls of said case, the recesses being opposite each other and extending in a direction from said ink supply portion toward a wall opposite the supply-side wall, each recess having a curved surface corresponding to a shape of said ink holding member;
• and
• said negative pressure generating member is held in contact with an entirety of the curved surfaces of said recesses with a compression rate of parts of said negative pressure generating member, which are positioned close to the recesses, being lower than that of parts between said flat portions.