A method of shot peening according to the present invention includes: placing a jig having an appropriate dimension at one face side of a stamped workpiece; and performing shot peening on another face side of the workpiece in a state where the jig is placed at the one face side of the workpiece, and conforming the workpiece to the jig. At this time, the shot peening may be performed in such a way that residual stresses in the inner side and the outer side of the curved part of the workpiece will become compressive stresses.