The authors proposed and fabricated a new microreactor stack which would be able to achieve a vertical fluid flow operation for the environment analysis, postgenome analysis, gene diagnosis, and screening of useful materials for medicine manufacture. This reactor is characterized as a simple structure with new aspects of the vertical fluid transportation using a proposed fluid filter with array of micro-through-bores. The deep x-ray lithography process using synchrotron radiation was used for the fabrication of the fluid filter. The feasibility of vertical liquid transportation was investigated using computational fluid dynamics analysis. It is indicated that the vertical liquid transportation is possible using the proposed fluid filter, and high efficiency mixing of liquid was also expected during transportation through the fluid filter. It was confirmed that the fluid flow velocity through the filter can be controlled by varying the load pressure around several kilopascals. A rapid enzyme reaction was successfully carried out and product concentration was observed using ultraviolet absorption spectroscopy. It was demonstrated that the proposed chemical reactor had a good vertical fluid flow operation performance for unit chemical operation. (c) 2006 American Vacuum Society.