Fast response and high durability hydrogen sensor is required in the safety management of hydrogen station and fuel cell vehicle. We had developed the catalytic combustion type hydrogen sensor in the shape of the miniature beads. It is using the optimized Pd-Pt/Al2O3 catalyst and the Pt micro-heater coil. Both warm-up time and response time of this sensor achieved less than 1 second by downsizing the element to 200?m diameter. Furthermore, we improved the resistance of sensor poisoning to silicone vapor and confirmed long term stability within +/-10%2of output error up to 8 years. Therefore, we assume that our sensor technology contribute to hydrogen safety.