To provide a form rolling die having very excellent practicability which can prevent damage on a tooth flank of a member to be form-rolled by suppressing interference between the member to be form-rolled and a form rolling tooth profile of the die in a relief part as much as possible.

The form rolling die form-rolls a desired tooth profile by causing an outer circumferential surface of the member to be form-rolled to plastically deform by abutting a form rolling tooth profile on the outer circumferential surface of the member to be form-rolled. The form rolling tooth profile is constituted by a leading part A, a finishing part B, and the relief part C, and a gradual decrease part of the tooth thickness in which a tooth thickness T of tooth parts of the form rolling tooth profile in the prescribed height position gradually decreases from a form rolling direction start end side to a form rolling direction terminal end side is provided on the relief part C, and the gradual decreasing part of the tooth thickness is constituted so that the gradual decreasing degree of the tooth thickness T on the form rolling direction terminal end side in the relief part C is larger than the gradual decreasing degree of the tooth thickness T on the form rolling direction start end side.