Advanced epitaxial techniques such as molecular beam epitaxy or metal-organic chemical vapour deposition have made it possible to grow interfaces between two semiconductors flat up to one atomic monolayer. The possibility of fabricating a heterostructure of strictly-defined parameters, a quasi-two-dimensional nature and sharp density of states, has stimulated both theoretical and experimental research and shortly found many applications including LEDs, lasers, high electron mobility transistors, IR photodetectors, etc. In this work a detailed study of optical properties of excitons in double quantum wells subject to magnetic and electric fields is presented. Starting from the well-known Luttinger formulae we developed an efficient way to solve the Schr”dinger equation of a coulombically-bound pair electron-hole forming an exciton. The results are illustrated on relevant figures, giving an opportunity to better understand the effects of external fields on the studied system. The book should shed light on methods used for calculations of magnetooptical properties and may be useful to anyone who is interested in theoretical or experimental research on semiconductor quantum structures.