At the end of 2019, the COVID-19 epidemic appeared in China, which already at the beginning of 2020 startedto spread around the world and grow from an epidemic into a pandemic that significantly affected all aspects of life. Before the outbreak of the COVID-19 pandemic, the European Union made efforts to fight climate changes and achieve climate neutrality sing the European Union Emissions Trading System (EU ETS) and the European Green Plan. The EU ETS is a system that covers about 36% of total greenhouse gas emissions in the European Union, such as the production of electricity and thermal energy, the production of cement, iron and steel, oil refineries and other industrial activities, and air traffic within the European economic area. As the spread of the COVID-19 pandemic led to the closure of factories through public policies and the creation of excess stock , greenhouse gas emissions from stationary sources recorded a decrease of 11.4%, which is the largest decrease in emissions since the ETS began operating, and this decrease is comparable only with a decrease recorded in 2009 at the height of the financial crisis. The pandemic affected not only greenhouse gas emissions, but also the supply, demand and prices of permits, and the largest emitter covered by the EU ETS: aviation. Therefore, the goal of this thesis is to analyze the impact of the COVID-19 pandemic on greenhouse gas emissions, on the supply and demand for EU ETS permits, and on their prices, and to draw a conclusion about the significance of the impact of the pandemic on the achievement of the intended goals of the EU ETS.