Silicon piezoresistive absolute pressure sensor for gas leakage alarm system was developed. This sensor must operate normally in the range of $0{sim}600;mmH_{2}O$ pressure, and $0{sim}100^{circ}C$ temperature. To make the most of this sensor for gas leakage alarm system, gas must not leak from the sensor itself when the diaphragm of the sensor fractures. Thus, the sealed diaphragm cavity was anodically bonded to pyrex 7740 glass under the condition of $10^{-4}$ torr, at $400^{circ}C$. The sensitivity of developed sensor was $4.06{mu}V/VmmH_{2}O$ for $600;mmH_{2}O$ full-scale pressure range. And temperature compensation method of this sensor is to change bridge-in put-voltage linearly in proportion to the temperature variation by using diode(PXIN4001) or Al thin film resistor. By these methods the temperature effect in the range of $0{sim}100^{circ}C$ was compensated over 80 % for offset drift, 95 % for sensitivity.