Capacitor

The embodiment of the utility model discloses a capacitor, which comprises a shell and a capacity cell which is arranged in the shell. The medium of the capacity cell is specifically an aluminum zinc metalized polypropylene film. When certain voltage is applied between two polar plates of the capacitor, accumulated charges cause partial discharge at weak points, temperature and voltage at the weak points are suddenly increased, intense discharge is further caused and the weak points are broken down. During discharging, thin metal layers adjacent to breakdown points are rapidly evaporated, the breakdown points spread around, electric insulation is formed in the areas of the breakdown points, arc is extinguished, continuous discharge and larger-area damages are prevented, the original electrical performance of the capacitor is immediately restored and the capacitor is enabled to have a self-healing ability.