A processed product manufacturing method includes preparing a workpiece containing metal and forming a plurality of first regions and a second region along a surface of the workpiece by the irradiation of a laser beam. The first regions are applied with a tensile residual stress. In the second region applied with a compressive residual stress, a plurality of irradiation points separated from each other in the surface of the workpiece are irradiated with the laser beam. The first regions are formed to be separated from each other and each of the first regions is surrounded by the second region when viewed from a direction orthogonal to the surface.