To provide a method and a apparatus for bending blade material which performs bending continuously in such a manner that the unprocessed part is not left on the end part of blade material when the belt-like blade material is bent in the crosswise direction.

Roller shape dies 4, 5 are pressed against a part near the blade top 12 of the blade material 1 having the blade top 12 on one edge of the crosswise direction and, thereby, the part is compressed and elongated in the longitudinal direction. The compressive elongation process is continuously performed while rotating the dies 4, 5. It is also possible that the blade material 1 is bent in a desired shape and, thereafter, the compressive elongation process is performed for the blade material 1. By repeating the compressive elongation process to the same part of the blade material 1, the curved quantity of the blade material can be increased.