Micromachining miniature microphone is one of the most challenging tasks in research and development today. For micromachining membrane, there is a significant internal (residual) stress, which strongly decreases the mechanical sensitivity of membrane. As predicted by theoretical analysis and numerical simulation, a corrugated diaphragm can greatly increase the mechanical sensitivity of the microphone diaphlagms due to the reduction of the initial stress effect without changing the process conditions. A silicon condenser miniature for crophone with corrugated diaphragm has been designed, fabricated and tested. The fabrication process is simple, efficient and fully compatible with standard IC process. Wafer level measurement has been carried out. An open circuit sensitivity of 40 my/Pa up to 7 kHz could be achieved under a low bias voltage of 10 V with only 1.5× 1.5 mm2 chip area. The preamplifier and subsequent signal process circuits are expected to be integrated in the same chip to make a complete micro-acoustic system. Micromachining miniature microphone is one of the most challenging tasks in research and development today. For micromachining membrane, there is a significant internal (residual) stress, which strongly decreases the mechanical sensitivity of membrane. As predicted by theoretical analysis and numerical simulation, a corrugated diaphragm can greatly increase the mechanical sensitivity of the microphone diaphlagms due to the reduction of the initial stress effect without changing the process conditions. A silicon condenser miniature for crophone with corrugated diaphragm has been designed, fabricated and tested. An open circuit sensitivity of 40 my / Pa up to 7 kHz could be under a low bias voltage of 10 V with only 1.5 × 1.5 mm2 chip area. The preamplifier and subsequent signal process circuits are expected to be integrated in the same chip to make a complete micro-acoustic system.