NOVELTY - Semi-finished flat product comprises (A) a core with a layer thickness of 0.3-5 mm, which is made of a continuously endless fibers-reinforced or long fibers-reinforced thermoplastic composite material, and is connected over the entire surface on upper- and/or lower side, with (b) at least one layer of a thermoformable thermoplastic molding composition, having a layer thickness of 0.1-3 mm. The core comprises 0.001-80 wt.% at least one reinforcing fiber having a fiber diameter of 3-40 mu m. The core with the layer of the molding composition, is constructed multilayered in a sandwich manner.    USE - The semi-finished flat product is useful in mechanically loaded components, preferably in motor vehicles, aircraft and wind turbines (all claimed).    ADVANTAGE - The flat product ensures improved thermal deformation compared to conventional semi-finished product.    DETAILED DESCRIPTION - Semi-finished flat product comprises (A) a core with a layer thickness of 0.3-5 mm, which is made of a continuously endless fibers-reinforced or long fibers-reinforced thermoplastic composite material, and is connected over the entire surface on upper- and/or lower side, with (b) at least one layer of a thermoformable thermoplastic molding composition, having a layer thickness of 0.1-3 mm, a comparable melting point as the matrix of the fiber-reinforced thermoplastic composite material or higher melting point, and a melt viscosity, which is greater by at least 10%, measured according to ISO 11443 at a residual moisture content of less than 0.03% and a molding temperature within shear rate of 1-100/s. The core comprises 0.001-80 wt.% at least one reinforcing fiber exhibiting a fiber diameter of 3-40 mu m. The core with the layer of the molding composition, is constructed multilayered in a sandwich manner. The molding temperature at the beginning of deformation, is at least 3 degrees C greater than the melting point of the material for the core and not greater than 10 degrees C greater than the melting point of the material of the layer of the thermoplastic molding composition.