This paper presents a novel, highly sensitive condenser microphone with a flexure hinge diaphragm. We used the finite-element analysis (FEA) to evaluate the mechanical and acoustic performance of the condenser microphone with a hinge diaphragm. And we fabricated the miniature condenser microphones with area of 1.5 mm${ imes}$1.5 mm. From the simulation results, we confirmed that the maximum displacements at the center of flexure hinge diaphragms are several hundred times, compared with flat diaphragms. The sensitivities of fabricated miniature microphones are about $12.87{mu}V/Pa$ at 1 kHz under a low bias voltage of 1 V, and the frequency response is flat upto 13 kHz.