A structure of micro-electro-mechanical-system microphone includes a substrate of semiconductor, having a first opening in the substrate. A dielectric layer is disposed on the substrate, the dielectric layer has a second opening, corresponding to the first opening. A diaphragm is located within the second opening, having an embedded part held by the dielectric layer and an exposed part exposed by the second opening. The exposed part has a junction peripheral region, a buffer peripheral region and a central region. The junction region has an elastic structure with slits, the buffer peripheral region includes a plurality of holes and is disposed between the junction peripheral region and the central region. A backplate is disposed on the dielectric layer above the second opening, wherein the backplate includes venting holes distributed at a region corresponding to the central part of the diaphragm.