A MEMS microphone includes a substrate having a cavity, a back plate disposed over the substrate, a diaphragm being disposed between the substrate and the back plate and being spaced apart from the substrate and the back plate and at least one anti-buckling portion provided between the substrate and the diaphragm. The diaphragm covers the cavity and the diaphragm senses an acoustic pressure to create a displacement. The anti-buckling portion is configured to temporarily support the diaphragm in case of a warpage of the diaphragm to prevent a buckling of the diaphragm. Thus, the MEMS microphone can prevent the diaphragm from generating a warpage by more than a predetermined degree, so that the diaphragm can have a tensile stress and the buckling phenomenon of the diaphragm can be prevented.