In this paper, we propose a filter system that can selectively obtain the required substances from an ar- tificial circulatory system. The blood circulatory system of the human body keeps us healthy. We consider this system to be useful for a robot system to maintain its condition. To realize an artificial circulatory system like a human body, it is important to deliver various substances with only a single vessel and extract only the required substances from them. We propose a method to deliver encapsulated substances. By using this method, each substance can be delivered without mixing for easy separation. We developed a filter system that can trap only the required substances without clogging based on differences in the capsule size. We conducted experiments to evaluate the separation per- formance of the system. We were able to obtain only the targeted substances with this system. We developed an im- purity filtration system as an application of our system.