A decoupling device including a lead frame and at least one capacitor unit assembly is provided. The lead frame includes a cathode terminal portion and at least two opposite anode terminal portions located at two ends of the cathode terminal portion. The two anode terminal portions are electrically connected with each other through a conductive line. The capacitor unit assembly includes multiple capacitor elements. The multiple capacitor elements of the capacitor unit assembly is connected in parallel, arrayed on the same plane and disposed on the lead frame. Each capacitor element has a cathode portion and an anode portion opposite to each other. The cathode portion of the capacitor element is electrically connected with the cathode terminal portion. The anode portion of the capacitor element is electrically connected with the anode terminal portion. When multiple capacitor unit assemblies exists, the capacitor unit assemblies are arrayed in a stacked way.