PURPOSE: To provide a disk brake which is excellent in wear resistance and ensures a given friction factor.

CONSTITUTION: A disk brake rotor comprises a rotor body 1 having a slide surface 10 formed of a base material being cast iron having flake graphite and narrow cured layers 3 formed in a radiation pattern and molten through irradiation with laser beams and cooled and exposed to the slide surface 10, and a ratio of the areas of the cured layers to that of the whole of the slide surfaces 10 is 10-40%. The cured layer 3 comprises a chilled layer 3a formed of cementite being main texture and formed through solidification of molten liquid and an annealed layer 3b formed below the chilled layer 3a and of martensite being main texture.