Formed article, structural member using the same, and manufacturing method of formed article

A long formed article made of one steel sheet, the formed article comprising:

• a top sheet portion which extends in a longitudinal direction;
• a standing wall portion which extends downward from each of both edges of the top sheet portion in a width direction;
• and
• a protrusion portion which is formed in a portion of the top sheet portion in the longitudinal direction by overlapping a portion extending toward an outside from each of both ends of the top sheet portion in the width direction and a portion extending toward the outside from an upper end of the standing wall portion,
• wherein in the longitudinal direction of the formed article, when a region provided with the protrusion portion is defined as a protrusion region and a region not provided with the protrusion portion is defined as a non-protrusion region,
• in the non-protrusion region, a recessed part extending in the longitudinal direction is formed in the top sheet portion, and
• a total value α of inner surface peripheral lengths of the top sheet portion and the standing wall portion in a cross section of the formed article perpendicular to the longitudinal direction in the protrusion region and a total value β of inner surface peripheral lengths of the top sheet portion, the standing wall portion, and the recessed part in the cross section of the formed article perpendicular to the longitudinal direction in the non-protrusion region satisfy 1.01≤β/α≤1.50, wherein
• the non-protrusion region having the recessed part is formed on at least one of both terminal ends in the longitudinal direction of the formed article.