Abstract: A device for attaching a disk-brake pad (2) to a piston (1) in a brake. The piston (1) has an opened internal volume (100) bordered by a chamfer (101) and exhibiting an internal peripherial widening (102). The device includes a passive fastening component (5) fastened to a backing (20) having an edge (50) detached from the backing (20) to define a gap (51) and an active fastening component (6) which is mounted to slide in the piston (1). The device is fastened to the pad (2) by first clips (61) inserted in the gap (51) and to the piston by second clips (62) inserted in the peripherial widening (102).