There is provided a liquid tank having a liquid remaining amount sensing module that makes it possible to reliably determine that the amount of ink has reached a predetermined value, in spite of its simple and compact configuration. In the ink tank, an information storage element and a module are provided on a ceiling portion of an ink accommodating chamber directly accommodating ink; the module having an optical reflector that faces downward in a vertical direction. A housing of the ink tank is composed of a transparent resin. Infrared light from an external light emitting section is incident on the optical reflector. The reflected light is received by a light receiving section and then, the quantity of light is measured.