The paper presents an attempt to characterize and classify the problems of chemical reaction engineering (CRE), with the emphasis placed on multiscale and multifunctional nature of these problems. The particular feature of CRE is the fact that the scope of this discipline extends from the microscale of the molecular level to the macroscale of complete industrial systems. Thus, chemical kinetics, catalysis, transport phenomena as well as modelling and optimization of chemical reactors form the core and the intellectual base for CRE. A short description of the theoretical fundamentals of each of the levels mentioned, including the possibilities of their practical application is presented. CRE plays a crucial role in the transfer of information across the boundaries of regions of different scales, to create a comprehensive and coherent basis-for the description of reactor processes. It is only such a quantitative description of the reactor systems that can be subjected to global optimization. Considerable progress in computer technology, numerical methods and analytical tools, coupled with enhanced skills in formulating the problems over the whole range from the micro- to macroscale are now the key elements in the industrial development of new processes and technologies. These new areas covered by CRE include the manufacture of advanced materials, microelectronics, biomedical and pharmaceutical technology. as well as the problems of environmental engineering.