The paper has three parts, (i) a brief overview of the main achievements made using mass spectrometry across all the fields of science, (ii) a survey of some of the topics currently being pursued most activity, including both applications and fundamental studies, and (iii) some hints as to what the future of mass spectrometry might hold with particular emphasis on revolutionary changes in the subject. Emphasis is given to ambient methods of ionization and their use in disease diagnosis and to their use in combination with miniature mass spectrometers for in-situ measurements. Special attention goes to the chemical aspects of mass spectrometry, including its emerging role as a preparative method based on accelerated bimolecular reaction rates in solution and on ion soft landing as a means of surface tailoring. In summary, the paper covers the proud history, vibrant present and expansive future of mass spectrometry.Keywords: ion chemistry, history of mass spectrometry, reaction rates, ion reactivity, mechanisms, instrumentation (Received October 12, 2012; Accepted October 16, 2012) Mass spectrometry may be defined, broadly, as the science and technology of ions. As such, it is a subject of enormous scope. The achievements of 20th century mass spectrometry now have come into focus. In rapid succession these include the measurement of mass/charge ratios of ions, 1) the discovery of isotopes, 2) and the utilization of isotope ratio measurements, 3) the measurements of mass defects, 4) and fundamental understanding of ionization, 5) fragmentation mechanisms 6) and the measurement of bond energies. 7) All this was achieved in the first half of the century and was made possible by advances in instrumentation including ionization methods, detectors and most importantly mass analyzers such as double focusing sector instruments. In the second half-century, organic mass spectrometry grew rapidly, starting with applications to petroleum distillates and moving quickly to natural products, steroids, and small-molecule drugs. 8) Gas chromatography/mass spectrometry was a key technology in early studies of biological systems. 9) Advances in instrumentation again fueled these advances, with ion optics becoming a significant scientific technology especially in Japan.10) A preoccupation with improving mass resolution and mass range became established and different types of mass analyzers were introduced for this purpose, including time-of-flight instruments 11) and quadrupole ion traps. 12) This quest drove biological mass spectrometry and propelled the development of ionization methods that were increasingly successful in handling both solid samples (desorption methods) 13)