A liquid container detachably mountable to a mounting portion of an ink jet recording apparatus, the liquid container includes a casing defining a liquid containing chamber; a supply port, provided in the casing, for supplying liquid contained therein to an ink jet head; a first engaging portion engageable with a first locking portion provided in the mounting portion, the first engaging portion being disposed on one side of the casing; a second engaging portion engageable with a second locking portion provided in the mounting portion, the second engaging portion being disposed opposed to another side of the casing, the another side being opposite the one side; a supporting portion for displaceably supporting the second engaging portion; an information storing portion for storing information relating to the liquid container; a contact electrically connectable with a contact provided in the mounting portion; a light emitting portion; a display portion for directing the light emitted from the emitting portion to an outside of the liquid container, wherein the supply port is provided in a side of the casing which is between the one side and the another side, and the contact is disposed in a region of a corner portion between the another side and the side having the supply port, the display portion is disposed adjacent an upper, in use, portion in the another side of the liquid container.