The panel is used in the construction of buildings. It ensures fire protection along the longitudinal sides. The panel has a step (1) on the left-side T-shaped side (2) of which a protection mass (3) is fitted obliquely at 45°C. A second protection mass (9) is formed in an oblique manner at 45°C in seat (4) made between the stem (5) of the right-side T-shaped side (6) and the cantelever part (7) of the external layer (8). Both protection masses (3, 9) are in contact between the length of their oblique sides (11) when every two adjacent panels (10) are connected./!
