This invention provides a drug delivery system that can accurately guide a magnetic drug by magnetic force to an affected part while confirming the position of the magnetic drug to a detailed point in the body. In the drug delivery system, a part or the whole of a living body is mounted on a stage, and a drug having a magnetic material injected into the living body is guided to an affected part of the living body. In the drug delivery system, blood vessel information including the position of a blood vessel branch part in a living body is acquired, and, based on the blood vessel information, control is carried out so that magnetic field generation means is disposed on the blood vessel branch part. Further, retention amount detection means for detecting the retention amount of the drug in the blood vessel branch part is provided.The magnetic force of the magnetic field generation means is regulated according to the retention amount of the drug detected by the retention amount detection means.
