A liquid container contains liquid to be supplied to a body of an image forming apparatus. The liquid container includes a liquid supply port part having a liquid supply port supplying the contained liquid and a cap member mounted on the liquid supply port part. The cap member has a sealing part sealing the liquid supply port and a holding part holding an information storage device storing information concerning the liquid. The sealing part and the holding part are separably connected together. When the cap member is mounted on the liquid supply port while the sealing part and the holding part are connected, the holding part is immovably fixed to the liquid supply port via the sealing part. When the sealing part has been separated from the holding part, the holding part comes to be able to move with respect to the liquid supply port.