The present invention provides a MEMS device, be implemented on many MEMS device, such as MEMS microphone, MEMS speaker, MEMS accelerometer, MEMS gyroscope. The MEMS device includes a substrate. A dielectric structural layer is disposed over the substrate, wherein the dielectric structural layer has an opening to expose the substrate. A diaphragm layer is disposed over the dielectric structural layer, wherein the diaphragm layer covers the opening of the dielectric structural layer to form a chamber. A conductive electrode structure is adapted in the diaphragm layer and the substrate to store nonvolatile charges.