Abstract: With the fast development of atom optics, a new subject has been created molecule optics, that studies the interaction of neutral molecules with electric, magnetic and light fields, as well as the cooling, trapping, manipulation and control of molecules. In this review the definition of molecule optics and its field of study are first presented. Secondly, the generation of cold molecular beams, the experimental preparation of ultracold molecular samples, ultracold molecular physics and spectroscopy, and nonlinear and quantum molecule optics are reviewed in some detail. Finally, the outlook on certain prospective applications of molecule optics is briefly summarized.