Condenser microphone and method for manufacturing the same

A condenser microphone comprising:

• a microphone unit;
• and
• a housing shaped to enclose said microphone unit to mechanically protect said microphone unit,
• said housing having a front end wall,
• said microphone unit comprising:
• an annular retainer having a front face oriented to face against said front end wall of said housing and a rear face;
• a movable diaphragm having a front face, a rear face and a peripheral edge attached to said rear face of said annular retainer, said movable diaphragm being placed in confronting relation to said front end wall of said housing and vibrated in response to an incident sound pressure wave through said front end wall of said housing;
• an annular spacer having a front face attached to said rear face of said movable diaphragm at the peripheral edge of said movable diaphragm and a rear face;
• a substrate connected to said rear face of said annular spacer, said substrate including a back electrode having an electret thereon and oriented in confronting relation to said movable diaphragm, said back electrode being operatively associated with said movable diaphragm to constitute a condenser, said condenser having a variable electrical capacitance;
• and
• a printed circuit board connected to said substrate and including an electronic component for generating an electric signal in response to said variable electrical capacitance,
• said microphone unit being mounted in said housing so that said annular retainer is sealingly held against said front end wall of said housing.