NOVELTY - The system has base elements i.e. building protection mats (104), located between plate-shaped elements for applying the plate-shaped elements (103) on a substrate, where limited stress is introduced on the plate-shaped elements during an applying process. The base elements are individually arranged on each plate-shaped element. The base elements are made of engineering plastic. The base elements comprise recesses for positive retaining of the plate-shaped elements and are formed in cuboid, linear or point shape. The substrate comprises a water-proof and weather-proof surface.    USE - System for applying plate-shaped elements i.e. photovoltaic modules, on a substrate such as soft roof e.g. building roof and industrial roof (all claimed).    ADVANTAGE - The base elements and the plate-shaped elements exhibit dead weight, so that the plate-shaped elements are applied on the substrate in a reliable manner. The limited stress is introduced on the plate-shaped elements during the applying process, thus avoiding damages at the plate-shaped elements and the substrate. The plate-shaped elements are applied on the substrate in a time-saving manner with minimum requirement of tools and manual effort. The base elements are made of engineering plastic, so that loads are introduced by the system on the substrate are not increased, thus avoiding requirement of a specific structure for the load-sharing and load retaining by the substrate, and hence enabling application of the plate-shaped elements on the substrate in a simple, material-saving and cost-effective manner. The substrate comprises the water-proof and weather-proof surface, thus protecting the plate-shaped elements against water and moisture, and hence preventing short-circuits while avoiding fungus growth or standing water columns.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for applying plate-shaped elements on a substrate.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic perspective view of a system for applying plate-shaped element, comprising base elements in form of mats.    Line connecting elements (101)    Connecting lines (102)    Plate-shaped elements (103)    Building protection mats (104)