A method for manufacturing a press-formed product (2,2A), comprising: forming a manufacturing intermediate by forming a planned outline portion including an undulating shape in a flat-sheet shaped blank sheet, as a planned portion for an outline portion which forms an outline of an outer circumferential portion of the press-formed product (2,2A); the planned outline portion includes a flat planned flat outline portion as a planned portion for a flat outline portion, and the flat outline portion is flat; and after the planned outline portion is formed from the blank sheet, the manufacturing intermediate is carried from a press forming machine that forms the planned outline portion to a different press forming machine that is used in a downstream process after the planned outline portion is formed, by carrying the manufacturing intermediate while supporting the planned flat outline portion using a carrier machine; maintaining a flat shape of the blank sheet in a region from the planned outline portion toward a center of the manufacturing intermediate, or forming an intermediate stretch-formed portion having a predetermined intermediate forming height (H2,H2A) in the manufacturing intermediate in a region from the planned outline portion toward a center of the manufacturing intermediate; forming a through-hole (18,18A) by piercing a flat portion as a portion where the flat shape is maintained or a stretch-formed-side top portion of the intermediate stretch-formed portion; and forming the flat portion after the through-hole (18,18A) is formed in the flat portion into a stretch-formed portion (9,9A) of a predetermined height (H1,H1A), or forming the intermediate stretch-formed portion after the through-hole (18,18A) is formed in the intermediate stretch-formed portion into the stretch-formed portion (9,9A) of the predetermined height (H1,H1A) that is greater than the intermediate forming height (H2,H2A). forming a manufacturing intermediate by forming a planned outline portion including an undulating shape in a flat-sheet shaped blank sheet, as a planned portion for an outline portion which forms an outline of an outer circumferential portion of the press-formed product (2,2A); the planned outline portion includes a flat planned flat outline portion as a planned portion for a flat outline portion, and the flat outline portion is flat; and after the planned outline portion is formed from the blank sheet, the manufacturing intermediate is carried from a press forming machine that forms the planned outline portion to a different press forming machine that is used in a downstream process after the planned outline portion is formed, by carrying the manufacturing intermediate while supporting the planned flat outline portion using a carrier machine; maintaining a flat shape of the blank sheet in a region from the planned outline portion toward a center of the manufacturing intermediate, or forming an intermediate stretch-formed portion having a predetermined intermediate forming height (H2,H2A) in the manufacturing intermediate in a region from the planned outline portion toward a center of the manufacturing intermediate; forming a through-hole (18,18A) by piercing a flat portion as a portion where the flat shape is maintained or a stretch-formed-side top portion of the intermediate stretch-formed portion; and forming the flat portion after the through-hole (18,18A) is formed in the flat portion into a stretch-formed portion (9,9A) of a predetermined height (H1,H1A), or forming the intermediate stretch-formed portion after the through-hole (18,18A) is formed in the intermediate stretch-formed portion into the stretch-formed portion (9,9A) of the predetermined height (H1,H1A) that is greater than the intermediate forming height (H2,H2A).