A liquid container is removably mountable into the apparatus body of a liquid ejection apparatus. The liquid container comprises a liquid storage chamber equipped with an air intake hole and a liquid supply port, for storing liquid and a valve unit having a sealing member and an urging member. The urging member is arranged so as to be at least partly rotationally movable and the urging member has urging force for urging the sealing member in the direction of making the sealing member abut the air intake hole. The sealing member is rotationally movable between a position of abutting and closing the air intake hole and a position separated from the air intake hole so as to open the air intake hole in response to a rotary motion of the urging member.