In recent years, citizens' attention to quality and air pollution has increased significantly. At present, odor pollution is considered to be a well-known environmental problem in connection with various industrial activities. The diploma thesis points out the importance of the effects of odor on human body, the perception of olfactory sensations and the very characteristic of the sensory receptor. It contains an extensive and detailed summary of odor measurement methods and monitoring options. It compares the legislation of Slovakia with the surrounding states of the European Union in field of air odors. It also discusses in detail the issue of biogas plants in Slovakia and Czech Republic. Smell as an air contaminant negatively affects the environment, especially human activity, his quality of life and safety, and also disrupts the normal way of doing economic activities.