The main goal of the project is study of double beta decay of ¹⁰⁰Mo and ¹¹⁶Cd in the framework of the NEMO 3 experiment. The project consists of experimental measurement, data analysis, and physical interpretation of results. The NEMO 3 detector was built by a large international collaboration, including institutions from France, Russia, Czech Republic, USA, UK, Finland, and Japan. The detector is located in the Modane Underground Laboratory (LSM) in France and has been taking data since June 2002. The interest of the Czech group in the experiment will be focused on the analysis of the following channels: two-neutrino and neutrinoless double beta decay of ¹⁰⁰Mo to the excited 0₁⁺ and 2₁⁺ states, two-neutrino and neutrinoless double beta decay of ¹¹⁶Cd. These analysis channels will produce very valuable and interesting results with regards to both particle and nuclear physics. At the same time, the group will participate in running of the experiment in the LSM and will guarantee the operation of an anti-radon system designed for removing radon from the laboratory air. This system will reduce the current radon background inside the detector by a factor of 20 to 50. This project involved also two diploma thesis and post-gradual students of the Czech Technical University in Prague.