Plastics are found in numerous products in our daily lives: packaging, textiles, electronics, cosmetics, etc. They make up a large part of municipal waste, which is very often not disposed of properly. This is how plastics end up in the environment. Once in the environment, the larger pieces of plastics are gradually broken down by physical or chemical action into tiny particles known as microplastics. Microplastics are a global environmental problem because they are ubiquitous and have harmful effects on health and the environment. Various analytical methods have been used to determine the amount and composition of microplastics in the environment. These methods are sometimes combined to produce more precise and accurate results. The analysis of additives released from microplastics can be an essential part of the characterization of these microparticles. This bachelor thesis focuses on microplastics and the sources of their occurrence in the environment. It also explains the classification of microplastics and the properties of plastic polymers commonly found in the environment. In addition, the most commonly used analytical methods for characterising microplastics are described, such as: SEM, FTIR, Raman spectroscopy, GC/MS, as well as some methods for analysis of the additives. In addition to these methods, some less common techniques are also mentioned.