Sliding shelves with manual or motor-powered movement allow to obtain the maximum extension of mobile shelves in the environments, where they are installed. Owing to the use of rails, it is possible, unlike fixed shelves, to use the travel range between the sliding of shelf and the other one, as an aisle, thus removing all the spaces, created among the fixed shelves. Sliding shelves can easily adapt to any environment and are recommended, above all, for libraries, museums and archives with large volumes. The sizing of the shelf is calculated according to the environments, the capacity that the client wishes to achieve and according to the material, which the shelves will be containing.