Abstract: This invention relates to a device for automatically securing a climber climbing a wall, wherein it comprises:a shaft guided in rotation,at least one drum comprising a groove for receiving a line wound around the drum at least once,an irreversible control member interposed between each drum and the shaft preventing a relative rotation between the drum and the shaft in a first direction and allowing rotation of the drum in a direction opposite the first direction,a system for continuously taking-up the slack of the line,and a means for controlling rotation of the shaft in a direction opposite that allowed by the irreversible control member, enabling the climber, who has fallen, to descend.