A MEMS microphone includes a substrate having a cavity, a back plate disposed over the substrate and having a plurality of acoustic holes, a diaphragm disposed over the substrate to cover the cavity, the diaphragm being disposed under the back plate to be spaced apart from the back plate, including venting holes communicating with the cavity, and sensing an acoustic pressure to create a displacement, a first insulation layer interposed between the substrate and the diaphragm to support the diaphragm, and the first insulation layer including an opening formed at a position corresponding to the cavity to expose the diaphragm, a second insulating layer formed over the substrate to cover an upper face of the back plate and an insulating interlayer formed between the first insulation layer and the second insulation layer, and the insulation interlayer being located outside the diaphragm and supporting the second insulation layer to make the back plate be spaced from the diaphragm. Thus, a process of manufacturing the MEMS microphone may be simplified.