The ink cartridge includes an ink supply port formed at a position, offset to one side, of a wall configuring an ink container body; a positioning projecting portion, formed on one wall out of two opposing walls adjacent the wall, whose upper surface and side portion are regulated in position when the cartridge has been mounted on a recording apparatus; a lever, formed on the other wall out of the two walls, maintaining a normal hinged-open state and having a projection that is forcibly displaced outward when the cartridge is mounted on the recording apparatus; and electrodes that are connected to a memory unit storing information on the ink in an ink container and formed on the positioning projecting portion.