Abstract: The electrolytic capacitor has an insulating casing, at least one capacitor element and multiple external terminals. The casing has multiple through holes and mounting protrusions. The at least one capacitor element is mounted in the casing and has multiple inner conductive pins connecting to a coil. Each external terminal is attached to a bottom panel of the insulating casing, connects to a corresponding inner conductive pin and has a main body, a connecting portion and two fixing portions. The connecting portion is formed on and extends from a side of the main body and has a conducting hole attached to a corresponding conductive pin. The fixing portions respectively extend from two ends of the main body and engage with the mounting protrusions. Each external terminal provides a soldering surface being flat and having large soldering area, therefore the electrolytic capacitor can be firmly soldered on a circuit board.