An ink cartridge comprising: an ink chamber storing ink; a communication chamber (30, 50) communicating the ink chamber with the exterior of the ink cartridge; a valve member (54, 68) disposed in the communication chamber such that the valve member (54, 68) is displaceable between a first position to shut off communication between the ink chamber and the exterior, and a second position to permit the communication; a biasing member (46, 63) including a side wall portion (36, 72) surrounding the valve member (54, 68), and an engaging portion (37, 73) extending inward from an end of the side wall portion (36, 72) and engaging with the valve member (54, 68), the biasing member (46, 63) normally holding the valve member (54, 68) at the first position but allowing the valve member (54, 68) to be placed at the second position by an elastic deformation of at least one of the side wall portion (36, 72) and the engaging portion (37, 73), and generating a biasing force to restore the valve member (54, 68) to the first position; and a disengagement preventer (70a, 71a; 30a, 50a; 75, 76a; 70, 71; 66; 62a) which prevents the valve member (54, 68) from disengaging from the engaging portion (37, 73) when the valve member (54, 68) is abnormally operated toward the second position; characterized in that the disengagement preventer includes a limiter (70a, 71a; 30a, 50a; 75, 76a) which limits the displacement of the valve member (54, 68) before the valve member (54, 68) disengages from the engaging portion (37, 73), wherein the limiter includes a direct contact portion (75, 76a) which is brought into direct contact with the valve member so as to inhibit the valve member from being displaced to such an amount that the valve member is disengaged from the engaging portion. an ink chamber storing ink; a communication chamber (30, 50) communicating the ink chamber with the exterior of the ink cartridge; a valve member (54, 68) disposed in the communication chamber such that the valve member (54, 68) is displaceable between a first position to shut off communication between the ink chamber and the exterior, and a second position to permit the communication; a biasing member (46, 63) including a side wall portion (36, 72) surrounding the valve member (54, 68), and an engaging portion (37, 73) extending inward from an end of the side wall portion (36, 72) and engaging with the valve member (54, 68), the biasing member (46, 63) normally holding the valve member (54, 68) at the first position but allowing the valve member (54, 68) to be placed at the second position by an elastic deformation of at least one of the side wall portion (36, 72) and the engaging portion (37, 73), and generating a biasing force to restore the valve member (54, 68) to the first position; and a disengagement preventer (70a, 71a; 30a, 50a; 75, 76a; 70, 71; 66; 62a) which prevents the valve member (54, 68) from disengaging from the engaging portion (37, 73) when the valve member (54, 68) is abnormally operated toward the second position; characterized in that the disengagement preventer includes a limiter (70a, 71a; 30a, 50a; 75, 76a) which limits the displacement of the valve member (54, 68) before the valve member (54, 68) disengages from the engaging portion (37, 73), wherein the limiter includes a direct contact portion (75, 76a) which is brought into direct contact with the valve member so as to inhibit the valve member from being displaced to such an amount that the valve member is disengaged from the engaging portion.