The invention can be defined in its most general form as a building unit, namely the sandwich panel with light core from corrugated sheet material in the form of zigzag crimp, and can be used in aircraft construction, as well as in shipbuilding and construction. Making use of the claimed invention will improve the weight efficiency, the strength and the manufacturability of the panel. The beneficial effect is attained due to the fact that a perforation line is formed along the zigzag lines enabling the adhesive material to get into the zigzag crimp through the holes of the perforation line in the course of zigzag core and skins assembling, thereby forming a head and a main body of the rivet.