To provide a drum in disk brake suppressing stress concentration that is repeatedly induced in a dust cover of the brake when the dust cover is bent by vibration during traveling of a vehicle.

A mounting face 56a of a mounting member 56 for the brake has an inclined face 56c in an outer circumference edge of the mounting face, the inclined face parting from a dust cover 54 toward the outer circumference edge and smoothly continuing from the mounting face 56a. As a result, when the dust cover 54 is bent and deformed toward the mounting member 56 by vibration during the traveling of the vehicle, the dust cover 54 is bent and deformed in the inclined face 56c side and comes in press-contact with the inclined face 56c. Thus, the outer circumference edge of the mounting face 56a can suppress stress concentration on the dust cover 54 from the mounting member 56, compared to an outer circumference edge of a mounting face of a conventional mounting member.