The invention relates to a double-layered sheet comprising two cover sheets (1, 2) with a space between them, and a fill material (3) which fills the space between said cover sheets. Said fill material is made of plastic, in particular of porous duroplastic plastic, comprising embedded hard bodies (6, 7, 8, 9). In order to obtain the best possible geometrical moment of inertia while keeping the weight per surface area low, and in particular in order to prevent shearing out under pressure, of the cover sheet (1) acting as a compression chord, during pressing together of the double-layered sheet, the fill material is characterised by at least two stress/strain characteristic curves. In particular the fill material comprises pores which are sealed off from each other. The plastic fraction of the fill material (3) which acts as a matrix for the hard bodies (6, 7, 8, 9) determines the softer stress-strain characteristic curve, while the hard bodies (6, 7, 8, 9) determine the harder stress-strain characteristic curve.