In this paper, a high‐performance silicon piezoresistive accelerometer, fabricated by bulk micromachining with an almost linear I/O (acceleration / voltage) relationship from 0 to 90g over a 400Hz bandwidth suitable for vehicle's safety system, is described. This accelerometer is composed of two glass cover caps and a Si sensing structure. The size of the sensing structure is 3.3mm × 2.05 mm × 0.15 mm. It consisted of a “mass”, a “frame”, and 4 thin beam “bridges”. The sensitivity of the accelerometer was found to be 9.6 × 10‐8(sec2/m) and a gauge factor of 18 was deduced from this value.