We discovered naturally collimated beam of surface acoustic wave (SAW) on balls and developed ball SAW sensor. It has an unique advantage of ultra-multiple roundtrips more than 100 turns. We achieved for the first time, sensing range of hydrogen from 10 ppm (0.001%) to 100% with a single sensor element, essential for hydrogen stations fuel cell cars. In this study, we describe the development of a MEMS palmtop gas chromatograph (GC) for organic volatile compound (VOC). It realized detection of hazardous gases in a reasonably short time, which will be applied for on-site monitoring of natural gas and fuel cell gases used at cars, home and smart grids.