A sandwich-structured composite panel , comprising - a first face skin of sheet metal, providing the façade surface of the panel , - a second face skin of sheet metal, providing the back surface of the panel , and - a core arranged between the first face skin and the second face skin, the first and second face skins being attached to the core, - an upper edge , comprising an upper edge skin construed from the sheet metal establishing the first face skin , - a lower edge , comprising a lower edge skin construed from the sheet metal establishing the first face skin , - an upper attachment element arranged in the upper edge , wherein - the upper attachment element comprises a first fixing surface , - the first fixing surface being attached to the second face skin of sheet metal, wherein - the façade surface of the panel is arranged in a first angle (A) in relation to the upper edge skin and the first fixing surface , - the upper attachment element comprises an upper extension for attaching another composite panel above the composite panel , - a lower attachment element is arranged in the lower edge , said lower attachment element comprising - a third fixing surface attached to the second face skin in the lower edge , and - the façade surface of the panel is arranged in a second angle (B) in relation to the lower edge skin and the third fixing surface characterized in that - said first angle (A) is more than 90°, that - the second angle (B) is less than 90°, and that - the lower attachment element comprises a groove-like counterpart arranged in use to receive the upper extension of an identical panel arranged beneath, wherein - the groove-like shape allows the upper extension to move therein. - a first face skin of sheet metal, providing the façade surface of the panel , - a second face skin of sheet metal, providing the back surface of the panel , and - a core arranged between the first face skin and the second face skin, the first and second face skins being attached to the core, - an upper edge , comprising an upper edge skin construed from the sheet metal establishing the first face skin , - a lower edge , comprising a lower edge skin construed from the sheet metal establishing the first face skin , - an upper attachment element arranged in the upper edge , wherein - the upper attachment element comprises a first fixing surface , - the first fixing surface being attached to the second face skin of sheet metal, wherein - the façade surface of the panel is arranged in a first angle (A) in relation to the upper edge skin and the first fixing surface , - the upper attachment element comprises an upper extension for attaching another composite panel above the composite panel , - a lower attachment element is arranged in the lower edge , said lower attachment element comprising - a third fixing surface attached to the second face skin in the lower edge , and - the façade surface of the panel is arranged in a second angle (B) in relation to the lower edge skin and the third fixing surface - said first angle (A) is more than 90°, that - the second angle (B) is less than 90°, and that - the lower attachment element comprises a groove-like counterpart arranged in use to receive the upper extension of an identical panel arranged beneath, wherein - the groove-like shape allows the upper extension to move therein. <EOS>