To provide a method for repairing a crack capable of being applied to a deep surface crack without requiring post-treatment such as heat treatment after an execution.

Each notch 2a, 2b, 3a and 3b which is substantially parallel with the crack 1 to be repaired and is shallower than the crack 1 is formed on both sides of the crack 1 across the crack 1. The notches 2a, 2b, 3a and 3b formed on both the sides of the crack 1 lower a stress expansion coefficient of the crack 1, and thereby a growth rate of the crack 1 can be slowed down and a possibility of destruction of a structure can be lowered.