The existing screening and characterization systems for biocatalysts operate in batch mode, which could make catalyst selection and process development inaccurate when continuous operation mode is required in industry. A significant improvement of an innovative screening system based on miniaturized multiple membrane reactors formerly presented by the author is outlined, which enables continuous feeding of substrates and continuous removal of products. Although the presented screening system was originally designed for homogeneous enzymatic reactions, it can be used without further modifications for continuous catalysis with polymer-bound chemical catalysts or for quasi-homogeneous systems like reverse micelles.