The article presents the conditions of admissibility of State aid in the European Union, taking into account the rules governing horizontal State aid. It offers an analysis of State aid granted by EU Member States is carried out under the provisions of the Treaty and the rules of State aid admissibility on the basis of regulations adopted by the European Commission in 2008 and 2014 on State aid provided under the framework for State aid for environmental protection. The analysis made it possible to verify the influence of State aid on economic growth and public finance in EU Member States which provided State aid for environmental protection in the years 2000–2015. The analysis was based on a linear regression model. The response variable (dependent variable Y) is: 1) the size of the GDP and 2) the size of general government sector debt, while the explanatory variable (independent variable X) is the expenditure on environmental aid.