Аннотация:Classes of astronomical objects and types of media containing the molecules are listed. Methods for cosmic dust and molecule study are reviewed briefly. Methods of the study of cosmic molecules and dust, molecules found in the interstellar matter and other astronomical objects, particular properties of chemical processes of molecule formation and destruction in rarefied cosmic media and influence of dust on the chemical processes are considered. Properties and structure of cosmic dust particles, the role of aromatic polycyclic hydrocarbons (PAH) and electric charge of dust grains are discussed