The general principle of the idea of separating our world into the smallest increments possible, atoms, started with Democrit (460–370 BC), the old Greek philosopher, who asked the origin of all questions: “What is that in truth being?” The efforts of scientists have – for a long time - had the goal to visualise these atoms by inventing tools to monitor the material world around us into its smallest possible increments. As a result, scientists involved in spectroscopy have created and established tools to identify the elemental composition of our material world and to measure the weight of atoms by a very special balance: the mass spectrometer. In this chapter, the history of mass spectrometry is described and highlights of the success story are given with a special emphasis on magnetic sector field mass spectrometry and its use in elemental and isotopic analysis. The roots of sector field instruments based on the observation of cathode rays and Kanalstrahlen, the first mass spectrometers and the determination of isotopes, the early commercialisation of mass spectrometry as well as the last 50 years of novel developments of mass separators and ion sources are covered to introduce give insight into the history of mass spectrometry.