An interference display unit with a first electrode, a second electrode and posts located between the two electrodes is provided. The characteristic of the interference display unit is that the second electrode's stress is released through a thermal process. The position of the second electrode is shifted and the distance between the first electrode and the second electrode is therefore defined. A method for fabricating the structure described as follow. A first electrode and a sacrificial layer are sequentially formed on a substrate and at least two openings are formed in the first electrode and the sacrificial layer. A supporter is formed in the opening and the supporter may have at least one arm on the top portion of the supporter. A second electrode is formed on the sacrificial layer and the supporter and a thermal process is performed. Finally, The sacrificial layer is removed.