The history of the practical use of the method began in the 1950s with a pioneering article by Australian scientist Alan Walsh, which described in detail a method for quantitatively determining the content of elements in solutions injected into an acetylene-air flame by absorbing light from selective radiation sources. Atomic absorption spectroscopy today is a simple and inexpensive high-precision method that is widely used in analytical chemistry. For five decades, scientists have worked to improve it. As a result, in 2004, Analyst Jena introduced a commercial product, the contrAA series, which revolutionized the concept of AAS as a single-cell low-throughput method. contrAA, with its appearance, opened up new possibilities of the method and became a key turning point in the development of AAS.