Sandwich structure is composed from layers. Border layers are from strong materials (steel, aluminium, FRG plates) and inside are soft and low-density materials (PUR foam, polystyrene). The first sandwich panels were used in aircraft industry. The airplane B-15 produced at 1945 was first airplane with sandwich wings. At present time the sandwich panels are frequently used in civil engineering structures as well. Because sandwich panel installation requires only a limited number of mechanical fasteners (e.g. screws), the resulting constructions avoid significant thermal bridging. To achieve distinctive architectural features, panels with hidden joints are available. Since 2009 a new European standard EN 14509 has defined the regulation and quality of sandwich panels with insulating core materials. In the case of static behavior of plates or beam types of structures we take into consideration the normal bending stresses and we neglect the effects of shear forces. If we have sandwich panels effects of shear forces is dominated and they must be taken into consideration. As introduction problem simple beam theory has been used. Finite Element Method taking into account the effect of shear forces has been used as well. Stiffness matrix was arranged using an idea that each column of stiffness matrix are forces related to unit displacements. Special computer program for solution of plane frames including effect of shear forces has been arranged. Sandwich panels are plates simply supported in opposite sides. This property is suitable for using Finite Strip Method. In this method combination of goniometric and polynomial function are used as basic variational functions. These types of basic function finally give orthogonal system of conditional equations. Number of numerical examples has been prepared with special computer program. Load bearing capacity of sandwich panel is limited with the maximum stresses in steel thin-walled plate. This problem can be calculated as elastic critical load on plate on elastic foundation. Assuming Winkler's elastic foundation the elastic critical load has been evaluated by analytical way. Finally comparison of theoretical ultimate load and load presented in tables of KINGSPAN factory has been arranged.