As a commercial vehicle providing low pollution and good fuel economy, we have developed a capacitor hybrid type medium duty truck. This is the first in the world. In the development of the Super Power Capacitor (high efficiency electric double layer capacitor) unit installed on the vehicle we aimed to establish a simple and easy method and process to manufacture the capacitor. We started from the development of materials and found the requirements for the capacitor itself and its manufacturing process. Based on these findings we constructed a capacitor production line in our factory. Major equipment is connected large size glove box with inert gas circulating and purifying device that control the production environment and an automatic laminator that enables the lamination of the capacitor cell. These equipments were designed and manufactured in-house. In this paper, the basic structure of the capacitor, efforts to develop the manufacturing method, the outline of the manufacturing process and measures to cope with certain problems in the process will be presented.