Mass spectrometry is a highly sensitive high-throughput instrumental analytical technique. It is used to determine the molecular mass, but also gives information on molecular structure amd is used for quantitation as well. Although it was developed over 100 years ago, it continues to evolve, both with respect to figures of merit (like sensitivity) and with respect to applications in various novel fields of science and technology. Mass spectrometry is capable of studying macromolecules (like proteins and protein complexes), and has very high sensitivity, now compounds at the atto- or zeptomol level can also be studied. Mass spectrometry can be coupled to separation techniques, and can be used to analyze complex mixtures, trace level compounds in biological matrices like active pharmaceutical ingredients or metabolites. In recent years in proteomics research has become a major new direction. In the present review we briefly introduce basic mass spectrometry techniques (ion surces, analyzers), combinations with chromatography (GC/MS, HPLC/MS), CEI MS) and tandem mass spectrometry. We also introduce two novel methods, mass spectrometry "imaging" and "lab-on-a-chip" technology.