A liquid cartridge storing liquid therein and configured to be mounted on a cartridge mounting portion during an intended use, the liquid cartridge, if orientated as in the intended use, comprising: a liquid supply port configured to provide communication between an interior and an exterior of the liquid cartridge; a first wall extending along an upward direction, a downward direction, a rightward direction, and a leftward direction and having the liquid supply port; a second wall spaced from the first wall in a rearward direction orthogonal to the upward direction and the rightward direction, the second wall extending in the upward direction, the downward direction, the rightward direction, and the leftward direction; a third wall between an upper end portion of the first wall and an upper end portion of the second wall, the third wall extending in a frontward direction, the rear direction, the right ward direction, and the leftward direction; and a prism having an irradiated surface configured to receive light emitted from a light emitting portion included in the cartridge mounting portion and change the state of received light in response to a level of stored liquid, a first storage chamber having a first communication opening (66, 158) and being confined by the first wall, the second wall and the third wall; and a second storage chamber extending between the first communication opening of the first storage chamber and the liquid supply port, the first and second storage chambers are positioned between the first and second walls, wherein: the liquid supply port is positioned below the third wall in the downward direction; the prism is positioned in the second storage chamber, and the irradiated surface is positioned above the third wall in the upward direction and positioned between the first wall and the second wall, characterized in that an upper end of the second storage chamber is at a higher level than an upper end of the first storage chamber so that a maximum liquid level in the second storage chamber is higher than a maximum liquid level in the first storage chamber. a liquid supply port configured to provide communication between an interior and an exterior of the liquid cartridge; a first wall extending along an upward direction, a downward direction, a rightward direction, and a leftward direction and having the liquid supply port; a second wall spaced from the first wall in a rearward direction orthogonal to the upward direction and the rightward direction, the second wall extending in the upward direction, the downward direction, the rightward direction, and the leftward direction; a third wall between an upper end portion of the first wall and an upper end portion of the second wall, the third wall extending in a frontward direction, the rear direction, the right ward direction, and the leftward direction; and a prism having an irradiated surface configured to receive light emitted from a light emitting portion included in the cartridge mounting portion and change the state of received light in response to a level of stored liquid, a first storage chamber having a first communication opening (66, 158) and being confined by the first wall, the second wall and the third wall; and a second storage chamber extending between the first communication opening of the first storage chamber and the liquid supply port, the first and second storage chambers are positioned between the first and second walls, wherein: the liquid supply port is positioned below the third wall in the downward direction; the prism is positioned in the second storage chamber, and the irradiated surface is positioned above the third wall in the upward direction and positioned between the first wall and the second wall, characterized in that an upper end of the second storage chamber is at a higher level than an upper end of the first storage chamber so that a maximum liquid level in the second storage chamber is higher than a maximum liquid level in the first storage chamber. the liquid supply port is positioned below the third wall in the downward direction; the prism is positioned in the second storage chamber, and the irradiated surface is positioned above the third wall in the upward direction and positioned between the first wall and the second wall, characterized in that an upper end of the second storage chamber is at a higher level than an upper end of the first storage chamber so that a maximum liquid level in the second storage chamber is higher than a maximum liquid level in the first storage chamber.