To provide a glass plate which enables the ID of an automobile to be identified without hindering passengers' visibility or being easily removed.

An identification code 11, which can be read with light of a wavelength outside the visible range, is applied onto a glass plate 10. The identification code is preferably a code patterned by an infrared reflecting film, an infrared absorbing film, an ultraviolet reflecting film, or an ultraviolet absorbing film and is preferably printed in the form of a bar code, a two-dimensional code, letters, English letters or symbols. The glass plate is preferably used as a windowpane for vehicles. The identification code, which can be read with light of a wavelength outside the visible range, is applied to a windowpane of a vehicle; the image of the windowpane by light is taken to extract the code from the image; and the ID of the automobile is identified based on the code.