Provided is an advertisement apparatus using a light switching device which
transmits or shields light according as a power source or heat is supplied or not.
The advertisement apparatus includes a light switching device transmitting light
when a power source or heat is supplied thereto and shielding light of less than
predetermined brightness when a power source or heat is not supplied thereto, or
operating in a reverse manner, and an illuminator for illuminating an image onto
the light switching device with light whose brightness is greater than the predetermined
brightness. The light switching device can be used as the window of a building,
and can present images of an advertisement using the illuminator for irradiating
light from a projector, for example, to the light switching device. Therefore,
the advertisement apparatus using a light switching device can be used for both
indoor and outdoor advertising displays.