The thesis instructively presents axions and axion-like particles as a plau- sible extension of the Standard Model of particle physics and discusses also the cosmological implications in the case of their existence as they present one of the most favourable dark matter candidates at given circumstances. The main part of the thesis is concerned with a search for axion-like particles at the NA62 experiment at CERN and a study of the gathered data and its impact on the data analysis.