A MEMS microphone includes a substrate (100), a supporting part (200), an upper polar plate (300) and a lower polar plate (400). The substrate (100) is provided with an opening (120) penetrating the middle thereof; the lower polar plate (400) straddles the opening (120); the supporting part (200) is fixed on the lower polar plate (400); the upper polar plate (300) is affixed to the supporting part (200); an accommodating cavity (500) is formed among the supporting part (200), the upper polar plate (300) and the lower polar plate (400); a recess (600) opposite to the accommodating cavity (500) is arranged in an intermediate region of at least one of the upper polar plate (300) and the lower polar plate (400), and insulation is achieved between the upper polar plate (300) and a lower polar plate (400).