Identification of microorganisms using the method of time-of-flight mass spectrometry has been widely used in various fields of microbiology for more than a decade. Despite the rather narrow applicability compared to other areas of proteomic analysis, this technology has developed significantly, making it a tangible competitor to the traditional bacteriological method. Basically, this became possible due to the expansion of databases of comparative mass spectra of microorganisms and the capabilities of specialized programs. However, in addition to determining the taxonomic affiliation, in clinical or research microbiology, problems are often solved to determine the structure, properties, or amount of specific proteins. The practical application of the results of proteomic analysis is very wide. In the field of medicine, this is the search for vaccines, markers of diseases of various etiologies, analysis of antibodies, monitoring the effectiveness of therapeutic measures. In bacteriology or virology, the study of the properties of an infectious agent, as well as the pathogenesis of the disease it causes. In recent years, the range of possibilities of proteomic and bioinformatics has been continuously expanding, and the methods themselves have been improved. The combination of modern software systems with the capabilities of analytical equipment makes it possible to supplement the results of proteomic analysis with data from the fields of genomics, transcriptomics, and metabolomics. Such a trend in the future will lead to the possibility of a comprehensive laboratory assessment of any changes in the cell of the microorganism. In addition, this will contribute to the emergence of the most accurate and universal taxonomic systematization of known species, taking into account data on their genomic and proteomic composition. This review briefly describes the application of existing methods of proteomic analysis to the study of individual proteins or their mixtures.