An ink cartridge includes: an ink storing member defining therein an ink storing chamber for storing ink; and a movable member which is provided in the ink storing chamber and is configured to be moved as an amount of the ink in the ink storing chamber decreases. The movable member includes a light shutting member which is movable in response to the motion of the movable member. The ink storing member includes a detected portion and the detected portion includes therein a passage in which the light shutting member is movably positioned and the passage is formed by a pair of walls that are substantially parallel to a moving plane on which the moving member moves. A pair of first spaces is provided between the light shutting member and the pair of walls. The detected portion includes at least one second space below the light shutting member, which is connected to the pair of the first spaces. The second space is narrower than one of the first spaces.
