Patent ID: 8848949

Claim:
A condenser microphone unit comprising: a diaphragm; a fixed electrode disposed opposite to the diaphragm with a gap therebetween and defining a capacitor together with the diaphragm; a cylindrical electrode having a first end and a second end, the first end being fitted to a periphery of the fixed electrode; a circuit board including electronic components mounted thereon and being in contact with the second end of the cylindrical electrode, the circuit board being electrically connected to the cylindrical electrode; a unit casing accommodating the diaphragm, the fixed electrode, the cylindrical electrode, and the circuit board; and a hollow insulating air chamber provided between an internal peripheral surface of the unit casing and an external peripheral surface of the cylindrical electrode; wherein the cylindrical electrode has a hole that connects an air chamber in a rear of the diaphragm and the hollow insulating air chamber.