We proposed and fabricated vertical micro reactor stack with vertical fluid flow operation available for the environment analysis, post-genome analysis, gene diagnosis, and screenings of the useful materials for the medicine manufacture. This reactor is characterized as the simple structure and new aspects of the vertical fluid transportation evoked by the use of the fluid filter with micro through-bores. The LIGA process using synchrotron radiation was applied for the fabrication of the fluid filters. The CFD simulation results suggested that the fluid can be held by the fluid filter and easily transported by the pneumatic operation. It was also confirmed that the fluid flow velocity through the filter was controlled by varying the loaded pressure around several kPa. Furthermore, it was expected that the fluid was stirred and mixed when passing through the fluid filter. It was demonstrated that a proposed chemical reactor had a good performance of the vertical fluid flow operation and chemical reaction. [DOI: 10.1380/ejssnt.2005.190]