To provide a vessel with a flange showing high rigid strength at a corner of the flange.

A blank satisfies necessary and sufficient conditions for folding and fixing formation, and a vessel with the flange is provided. All of various candidates for bond margins enabling fixing formation irrespectively of degrees of effects/demerits are searched and collected in the surrounding of a deformed fan-like part p made by folding various blanks, and classified into the front surface and reverse surface of the blanks. Mutual combinations of both the classified candidates for the bond margins are displayed in a matrix, and policies of all the combinations are tried and applied for many kinds of various blanks. Then the degrees of usefulness represented by an effect/demerit for shaping performance are compared and evaluated in the vessels made by successive folding formation and fixing formation.