To provide a tube stock that has a deformed a cross section, is inexpensively produced at a high productibility and easily miniaturizes a structural body.

The tube walls 21 of the tube stock 20 having the deformed cross section are formed of the 1st and the 2nd wall parts 21a and 21b which are opposed to each other in the 1st direction and the 3rd and the 4th wall parts 21c and 21d which are opposed to each other in the 2nd direction crossing the 1st direction. The tube stock 20 is formed so that the 1st outside diameter of the tube stick in the 1st direction which is specified with the 1st and the 2nd wall parts 21a and 21b is changed in the longitudinal direction, moreover the 1st and the 2nd beads 21c1 and 21c2, 21d1 and 21d2 projecting outwards are formed on the outsides of the 3rd and the 4th wall parts 21c and 21d by extrusion and the widths F1 and F2 of the 1st and the 2nd beads 21c1, and 21c2, 21d1 and 21d2 in the 1st direction are equal to each other over the entire length of the tubular material 20.