In a device (1) for the defibrillation of a heart (2) with an implantable cardiac pacemaker and defibrillator (3), the defibrillation electrode (4) is arranged on the stimulation electrode (5), with the stimulation electrode enclosing the defibrillation electrode. In order to be able to remove the defibrillation electrode without a complicated operation if a defect in the defibrillation electrode (4) occurs during use, it can be moved relative to the stimulation electrode (5) and can be retracted and replaced relative to the implanted stimulation electrode (5) from its position of use, for which the stimulation electrode (5) can be detached or separated from the cardiac pacemaker (3) or its plug (9) provided on this pacemaker.
