A method for manufacturing a hat-shaped cross-section component includes a gripping process, a bending and stretching process, and a bend back process. In the gripping process, a pair of vertical walls of an elongated preliminarily formed component that has been formed into a hat-shaped cross-section formed into a hat shaped cross section profile are disposed at a width direction outside of a punch, and a top plate of the preliminarily formed component is gripped using the punch and a pad. In the bending and stretching process, after the gripping process, a die provided on both width direction sides of the pad is moved toward the punch side relative to the preliminarily formed component, and the die is used to bend and stretch the vertical walls toward the opposite side to the top plate at one side in the length direction of the preliminarily formed component. In the bend back process, after the gripping process, a holder provided on both width direction sides of the punch is moved toward the pad side relative to the preliminarily formed component, and the holder is used to bend back the vertical walls toward the top plate side at another side in the length direction of the preliminarily formed component.