a liquid container detachably mountable to a mounting portion of an apparatus , the mounting portion including a first locking portion and a second locking portion , the liquid container including a casing for containing liquid and a supply port for supplying the liquid to an ink jet head , the liquid container includes a first engaging portion provided at a first side of the casing and engageable with the first locking portion ; a second engaging portion provided opposed to a second side of the casing which is opposite the first side , the second engaging portion being engageable with the second locking portion ; a supporting member for displaceably supporting the second engaging portion ; a contact contactable to a member provided in the mounting portion to permit information display means to display information relating to the liquid container , wherein the supply port is disposed in a third side of the casing which is between the first side and the second side , and the contact is disposed at a corner region between the second side and the third side .