To provide a foldable document capable of being easily folded and opened.

Rectangular paper P is arranged so as to become long laterally and four quadrants are defined by an xx synmetric axis and a yy synmetric axis. The fold line in the first quadrant becomes a hill form folding line 21A extending in a 45° right downward direction from the crossing point 31A of the yy axis and the upper edge of paper, a trough form folding line 11A further extending therefrom to the xx axis, the trough form folding line 12A from the end point 34A of the hill form folding line 21A to the yy axis in parallel to the upper edge of the paper, the trough form folding line 13A from the end point 34A to the upper edge of the paper in parallel to the yy axis, the hill form folding line 22A from the crossing point 32A of the trough form folding line 11A and the xx axis to the upper edge of the paper in parallel to the yy axis, the trough form folding line from the crossing point 32A to the right edge of the paper in a 45° right upward direction, the hill form folding line 23A from the upper edge of the paper to the middle point along the yy axis and the trough form folding line 16A from the middle point to the xx axis. Each of other quadrants becomes a folding line axisymmetric to the first quadrant.