To provide a method of adjusting a surface contact of a brake in order to improve brake torque of a disc brake which generates braking force by a biasing force of a spring.

In an embodiment, a method of adjusting a surface contact of a brake includes: a step to fit a polishing disc 30 to a rotary shaft 5; a step to polish a pressure contact surface 21 by rotating the polishing disc 30; and a step to fit a brake disc 25 to the rotary shaft 5. The polishing disk 30 includes a polishing material 31 in a surface facing the pressure contact surface 21 of an armature 20. The step to fit a polishing disc 30 to the rotary shaft 5 is performed in a state that the brake disc 25 is removed from the rotary shaft 5. The step to polish the pressure contact surface 21 by rotating the polishing disc 30 is performed while pressing the armature 20 to the polishing disc 30 by a biasing force of a spring 15. The step to fit the brake disc 25 to the rotary shaft 5 is performed after polishing the pressure contact surface 21, by removing the polishing disc 30 from the rotary shaft 5.