The storage box is formed from a sheet provided with a plurality of folding lines defining a parallelepiped provided with six faces. One of the faces is a hinged lid, and it is characterised in that the opposed face to the hinged lid comprises a first sector provided with an oblique folding line that defines a first joining zone. A second sector also provided with an oblique folding line that is joined to the first sector in the first joining zone; and a third sector is provided with an oblique folding line that defines a second joining zone; and a fourth sector that is joined to the third sector in the second joining zone.