A structure for informing a state of the ink tank by a light emitting section such as LED, capable of displaying such information at a position easily visible by the user and favorably sending the emitted light both to the user and a light receiver section on the printer side without needing electric wiring which may disturb the user's visibility or manipulation. The light emitting section is separated from the display section and a light guiding section is provided between the both. A member for suitably limiting the emission of light is provided in the display section. Thereby, it is possible to dispose the display section at the best position without needing the electric wiring on the ink tank and obtain a preferable light volume suitable both for the improvement in user's visibility and the stability of the operation of the light receiving section.