The authors report the radioisotope-powered ion gauge (RPIG) using the safe, low activity, planar radioactive (63)Ni beta thin-film source as the cold cathode. RPIG has both high stability and long lifetime with (63)Ni half-life of 100.1 years. The authors experimentally demonstrate an ultrahigh sensor dynamic range, from high vacuum (10(-6) Torr) to high pressure (10(3) Torr), which is the largest sensitivity range among all the reported pressure sensors. With high source stability independent of temperature, and its self-powered nature, RPIG is a promising candidate for pressure measurement, which needs extreme low temperature or high temperature, in microsystems where power consumption and system complexity need to be minimized. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3483579]