A flexible container for packaging solid particulate materials in bulk, comprising a bottom (1), four essentially rectangular outer lateral walls (2) and a cap (3), characterized in that, inside the flexible container, a tube made of a flexible material, having a height less than the height of the outer lateral walls, is fixed by vertical fixing lines (5) to the four outer lateral walls (2) of the container so as to define a central compartment (4) and four peripheral compartments (7a, 7b, 7c, 7d) separated from the central compartment respectively by four inner walls (8a, 8b, 8c, 8d), each of the inner walls having, on its top edge, a central pouring means (11).