A hat shaped cross-section component manufacturing method comprising: a supporting process of disposing a semi-finished formed component (10; 501; 100; 110; 120; 130; 140; 150; 70; 700) with a hat-shaped cross-section between a restriking punch and a restriking die that are disposed facing each other, and supporting a top plate (11; 501c; 102; 112; 122; 132; 142; 152; 702) of the semi-finished formed component from the restriking punch side using a support member extending from the restriking punch toward the restriking die side; characterized by : a positioning process of housing the top plate inside a first recess portion configuring a top face side of a forming recess that is formed to the restriking die and that is open toward the restriking punch side, gripping the top plate using the support member and the restriking die , and positioning the semi-finished formed component in a width direction using the first recess portion and a pair of vertical walls (12a,b; 104, 106; 114, 116; 124a,b; 134, 136; 144, 146; 154, 156; 501a,b; 704a,b) that extend from both width direction ends of the top plate of the semi-finished formed component; and a restriking process of inserting the restriking punch inside a second recess portion configuring an opening side of the forming recess and set with a larger width dimension than the first recess portion , and restriking the semi-finished formed component using the restriking punch and the restriking die . a supporting process of disposing a semi-finished formed component (10; 501; 100; 110; 120; 130; 140; 150; 70; 700) with a hat-shaped cross-section between a restriking punch and a restriking die that are disposed facing each other, and supporting a top plate (11; 501c; 102; 112; 122; 132; 142; 152; 702) of the semi-finished formed component from the restriking punch side using a support member extending from the restriking punch toward the restriking die side; characterized by : a positioning process of housing the top plate inside a first recess portion configuring a top face side of a forming recess that is formed to the restriking die and that is open toward the restriking punch side, gripping the top plate using the support member and the restriking die , and positioning the semi-finished formed component in a width direction using the first recess portion and a pair of vertical walls (12a,b; 104, 106; 114, 116; 124a,b; 134, 136; 144, 146; 154, 156; 501a,b; 704a,b) that extend from both width direction ends of the top plate of the semi-finished formed component; and a restriking process of inserting the restriking punch inside a second recess portion configuring an opening side of the forming recess and set with a larger width dimension than the first recess portion , and restriking the semi-finished formed component using the restriking punch and the restriking die . a positioning process of housing the top plate inside a first recess portion configuring a top face side of a forming recess that is formed to the restriking die and that is open toward the restriking punch side, gripping the top plate using the support member and the restriking die , and positioning the semi-finished formed component in a width direction using the first recess portion and a pair of vertical walls (12a,b; 104, 106; 114, 116; 124a,b; 134, 136; 144, 146; 154, 156; 501a,b; 704a,b) that extend from both width direction ends of the top plate of the semi-finished formed component; and a restriking process of inserting the restriking punch inside a second recess portion configuring an opening side of the forming recess and set with a larger width dimension than the first recess portion , and restriking the semi-finished formed component using the restriking punch and the restriking die . <EOS>