US Patent 10968581 Magnetic marker and magnetic marker detection system

Provided are a magnetic marker and a magnetic marker detection system with a reduced magnetic force. The magnetic marker detection system (1S) in which magnetism generated from the magnetic marker (1) laid on a road surface (53) is detected by a magnetic sensor (2) attached to a vehicle's body floor (50) of a vehicle (5) is a system with the magnetic marker (1) and the magnetic sensor (2) in combination, the magnetic marker having a surface with a magnetic flux density equal to or smaller than 40 mT and the magnetic sensor using a magneto-impedance element including an amorphous wire as a magneto-sensitive body with impedance in a high-frequency region changing in accordance with an external magnetic field.