In this paper we demonstrate a microfluidic device that immobilizes microbes into microporous carrier using positive dielectrophoresis (DEP). This device can characterize bacteria, while precisely controlling the reaction conditions and the number of bacteria involved in the biochemical reaction, and can effectively screen them to efficiently produce useful chemicals by fermentation, such as organic acids, antibiotic drugs, and foods. We chose microbes belonging to Corynebacterium group as samples. First, as preparing for using the microfluidic device, we experimentally deduced effective DEP frequency of 10 MHz, when live C. glutamicum was preferably driven to the areas with stronger electric fields. Second, we characterized the microfluidic device and found that the device could immobilize microbes into micro pores and evaluate the production capacity of a single bacrerium. As the demonstration, we used the developed device to characterize microbes under various environments and evaluate biological activity.