Abstract: A collapsible or foldable container formed by sheet material comprising at least a bottom (15), a first pair of opposite side walls (12) (14) and a second pair of opposite side walls (11) (13). The bottom (15) and the second pair of side walls (11) (13) are respectively provided with folding guider means along their middle lines (42) (29) (32) which are coplanar. Also the two legs of two respective isosceles triangles defined by two isosceles triangular zones at the lower part of the two side walls (11) (13) are also provided with folding guider means. Thus the container can be easily collapsed into a planar structure to facilitate its carrying, storage, transport or disposal.