An implantable electrical stimulating device (110, 124, 132, 140-t1, 140-t2, BAT1, MP1) is disclosed comprising an electric energy storage unit (BAT1), controlling electronics (MP1), a supporting structure (132), active electrodes (140-t1) and supercapacitors (140-t2) for shaping an electric field. The device is suitable for the heart, brain, other organs and general cells. The supercapacitor ensures a high stored charge and a high electric field magnitude.