The understanding of the events taking place in a cell, a biological fluid or in any biological system is the main goal of biology research. Many fields of research use different technology to assess those events. Mass spectrometry is one of those techniques and this undergoes constant evolution and adaptation to always enhance the accuracy of the information provided. ProteomicsÂ{u0CAF}vides a large panel of data onÂ{u0CAF}tein identity andÂ{u0CAF}tein expression that were made possible by mass spectrometry. For several years now mass spectrometry has become central to performing proteomic research, however this powerful tool is under constant evolution to be more sensitive and more resolute. More importantly mass spectrometry became a field of research focusing on new applications. Indeed, the complexity in biological systems relies on the changes of expression of transcription of proteins but also on the post-translational modification of proteins, the structure of proteins and the interaction between proteins, amongst others. As of now, several investigations tried to improve the quantification of proteins by mass spectrometry, the determination of post-translational modifications, the protein-protein and protein-nucleic acids interaction or the proteins structures. This bookÂ{u9CE0}structured as follows: after a brief introduction of the usual and most popular applications for mass spectrometry in proteomics,Â{u4A25} most recentÂ{u2973}earch and developments inÂ{uD873}s spectrometry-based methodologies will be explored.