Provided is a defibrillation system including an electrode section that is attached to a heart and applies electrical energy to the heart, a defibrillator that generates the electrical energy on the basis of a predetermined defibrillation wave, and a lead that electrically connects the electrode section and the defibrillator. Further, the defibrillation wave includes a first wave generating first energy, a second wave generating second energy higher than the first energy of the first wave behind the first wave, and an application stop period formed between the first wave and the second wave.
