<p>An electret capacitor microphone having a reduced parasitic capacitance and a higher sensitivity. The electret capacitor microphone comprises a capacitor section (3) having a fixed electrode (2) with an electret member (11) and a vibratory membrane electrode (1), a case section (7) containing the capacitor section (3), a base (5) having a converting circuit (4) for converting a variation of a static capacitance of the capacitor section (3) caused by the vibration of the vibratory membrane electrode (1) into an electric signal and outputting the electric signal, and an electric connection section (6) provided inside the case section (7) and adapted for electrically connecting the capacitor section (3) to the base (5). The distance between the outer side of the capacitor section (3) and the case section (7) varies in the circumferential direction of the capacitor section (3) when they are viewed from above. The shape of the case section (7) when viewed from above is different from that of the capacitor section (3) when viewed from above.</p>
