An electret condenser microphone includes a case, a diaphragm electrically connected to the case, a fixed electrode plate disposed opposing the diaphragm with a spacer interposed therebetween, the fixed electrode plate being formed of a metal plate coated with a polymer film on which an electret is formed, an insulating ring for insulating the fixed electrode plate from the case, a printed circuit board (PCB) defining a back chamber with the fixed electrode plate, and an integrated base for supporting the fixed electrode plate and the PCB and electrically connecting the fixed electrode plate to the circuit component embedded in the PCB through a connecting terminal. The integrated base includes a hollow cylindrical insulating body and metal plating layers formed on the top and bottom of the insulating body. Outer diameters of the metal plating layers are less than the insulating body and are electrically connected by a conductor.