A magnetic body may be suitably applied to a drug delivery system using magnetism. Furthermore, a drug delivery control device allows the magnetic body to be suitably applied to drug delivery. The magnetic body includes a magnet and a cover part attached to an edge of the magnet. The cover part is composed of a material with high magnetic permeability, and a ratio of a length to a radius of the cover part is 10:1 to 7:3. The drug delivery control device includes the magnetic body, a head for supporting the magnetic body and a drive mechanism of the head that causes the head to operate along a projected region formed by the affected area with respect to a surface of a tissue. A magnetic field is applied from the magnetic body to the affected area where a magnetic drug is administered.