Fiber optic interferometry pressure sensor is an excellent diaphragm-base measurement system. It is in-vivo medical device to measure local blood pressure by using endoscopic procedures via the blood vessels and the heart. The sensor must smaller than the size of human artery. This paper has concentrated on the MEMS technology in order to build the sensor tip using micromachining process to the proposed Fabry-Perot Interferometry (FPI) micro-pressure sensor. The feasibility of bulk, surface and hybrid micro-machining as viable proposition for sensor fabrication are reviewed. This paper will address the various factors involved in the manufacturing of FPI sensors, which gives high yield with a specific level of performance. The reliability of the sensor tip has been discussed.