Cardboard tray folded from an unfolded sheet (1; 20; 40; 60) of cardboard, which tray comprises: - a bottom wall (2; 21; 41; 61) with a circumferential edge composed out of a number of straight edges; - wall parts (3; 22; 42; 62) each arranged to a straight edge of the bottom wall (2; 21; 41; 61); - first flange parts (5, 6, 7; 23, 24, 25; 44, 45, 46; 64, 65, 66) at least arranged to opposite wall parts (3; 22; 42; 62) along the circumferential edge, which first flange parts (5, 6, 7; 23, 24, 25; 44, 45, 46; 64, 65, 66) are arranged to an edge of said wall part (3; 22; 42; 62) opposite of, and preferably parallel to, the respective straight edge of the bottom wall (2; 21; 41; 61); wherein the first flange parts (5, 6, 7; 23, 24, 25; 44, 45, 46; 64, 65, 66) comprise at least a first (5; 23; 44; 64), a second (6; 24; 45; 65) and third (7; 25; 46; 66) elongate flange part section, which are connected parallel and along an elongate edge to each other, wherein, for each first flange part, the first elongate flange part section (5; 23; 44; 64) is arranged to a respective wall part (3; 22; 42; 62), the second elongate flange part section (6; 24; 45; 65) is double folded against the first elongate flange part section (5; 23; 44; 64), and the third elongate flange part section (7; 25; 46; 66) is connected parallel and along an elongate edge to the second elongate flange part section (6; 24; 45; 65) characterized in that for each first flange part (5, 6, 7; 23, 24, 25; 44, 45, 46; 64, 65, 66) the third elongate flange part section (7; 25; 46; 66) is adhered to the respective wall part (3; 22; 42; 62) on the inside of the cardboard tray and the second elongate flange part section (6; 24; 45; 65) is sloping downwards from the third elongate flange part section (7; 25; 46; 66) towards the first elongate flange part section (5; 23; 44; 64). - a bottom wall (2; 21; 41; 61) with a circumferential edge composed out of a number of straight edges; - wall parts (3; 22; 42; 62) each arranged to a straight edge of the bottom wall (2; 21; 41; 61); - first flange parts (5, 6, 7; 23, 24, 25; 44, 45, 46; 64, 65, 66) at least arranged to opposite wall parts (3; 22; 42; 62) along the circumferential edge, which first flange parts (5, 6, 7; 23, 24, 25; 44, 45, 46; 64, 65, 66) are arranged to an edge of said wall part (3; 22; 42; 62) opposite of, and preferably parallel to, the respective straight edge of the bottom wall (2; 21; 41; 61); wherein the first flange parts (5, 6, 7; 23, 24, 25; 44, 45, 46; 64, 65, 66) comprise at least a first (5; 23; 44; 64), a second (6; 24; 45; 65) and third (7; 25; 46; 66) elongate flange part section, which are connected parallel and along an elongate edge to each other, wherein, for each first flange part, the first elongate flange part section (5; 23; 44; 64) is arranged to a respective wall part (3; 22; 42; 62), the second elongate flange part section (6; 24; 45; 65) is double folded against the first elongate flange part section (5; 23; 44; 64), and the third elongate flange part section (7; 25; 46; 66) is connected parallel and along an elongate edge to the second elongate flange part section (6; 24; 45; 65) characterized in that for each first flange part (5, 6, 7; 23, 24, 25; 44, 45, 46; 64, 65, 66) the third elongate flange part section (7; 25; 46; 66) is adhered to the respective wall part (3; 22; 42; 62) on the inside of the cardboard tray and the second elongate flange part section (6; 24; 45; 65) is sloping downwards from the third elongate flange part section (7; 25; 46; 66) towards the first elongate flange part section (5; 23; 44; 64).