PURPOSE: To form grooves or holes in both faces at the brake section, by applying discharge processing on a disc brake plate.

CONSTITUTION: A plate 1 completed of entire finish process is placed in a liquid tank 5 and secured. Processing liquid of the amount sufficient for immersing the plate 1 is injected in said tank 5. The discharging section 9 having the shape and size corresponding to those of all grooves or holes to be formed at the brake section 4 of the plate 1 is provided while projecting from one face of the substrate 8 of the electrode 7 in a discharge processing equipment. Then the discharging section 9 is brought near to the surface of the plate 1 in the tank 5 and required voltage is applied on the electrode 7 to fuse the portion of the brake section 4 corresponding to the discharging section 9 through discharge to form the groove in each face separately and to form the hole while penetrating through one face.