Abstract: A glass supporting device of a scanner comprises an upper cover, a lower cover, a front cover, and a glass sheet. The upper and lower covers, and the front cover can be integrated. The lateral sides of the upper cover are installed with a plurality of sliding tracks. The sliding tracks and the edges of the top of the upper cover are formed with a shape track. Therefore, the glass sheet can be slid into the track manually for being positioned therein. The track serves for supporting the glass sheet. In the present invention, the glass sheet is easily assembled and detached. The upper cover and glass sheet is updated independently. Therefore, the assembling work is performed quickly and the cost for detaching parts are low.