The CryoReactor was originally developed to perform continuous small-scale organometallic reactions at low temperatures. The essential prerequisites were precooling of the reactants, mixing at low temperature and chemical transformation in a cooled delay loop ensuring a definite residence time. In order to meet these requirements, a system was designed comprising two capillary-type heat exchangers, a multilamination micromixer and a reaction capillary which are placed together into an insulated steel vessel (“Dewar”) filled with a cryogenic agent. Accordingly, the CryoReactor combines several functions and can be regarded as an integrated unit.