This invention provides a small-sized capacitor capable of improving the capacitance intensity, improving selection of electrode metal and dielectric medium materials, and simplifying the manufacturing project. A capacitor element (12) includes a pair of conductive layer (14) and (16); a plurality of first electrodes (20) and second electrodes (24); and insulation caps (22) and (26) for insulating these electrodes and the conductive layers. By anodizing a metal substrate in two stages, holes filled with the first electrodes (20) and holes filled with the second electrodes (24) are randomly distributed. The decision capacitance area can be increased by enabling the first electrodes (20) and the second electrodes (24) to be the prismatical, and the high capacitance property to the capacitor(10) can be realized. In addition, the selection of the electrode material can be increased and the manufacturing process can be simplified.