A substrate on which a plurality of thin films having a plurality of cross-sections corresponding to the cross-section of a micro-structure are formed is placed on a substrate holder. After such condition is satisfied, some of the ranks will have converged. Therefore, a silicon condenser microphone fabricated by using the method may have improved sensitivity by increasing the small back chamber space of the a micro electro mechanical system chip itself and reduced noise including total harmonic distortion. In the extended position, the prongs will at least damage the item of merchandise protected by the security storage container.