A 1/2-in. bias-typed measurement condensor microphone with high sensitivity as well as its measurement of 1 in. has been developed. In this microphone, the diaphragm is welded to the body by means of a laser welding technique. From this, a reduction of tension of the diaphragm is restrained; therefore, it is able to ensure long-term stability. A wide frequency range (up to 14 kHz) and a high sensitivity are compatible by optimizing the tension of the diaphragm, structure of the back plate, and gap of diaphragm to the back plate. Furthermore, a very low temperature coefficient can be achieved using suitable material for the backplate.