Angle detecting apparatus and a position detection device

A magnet rotor having a multipolar segment magnets, an angle detection apparatus having a magnetic sensor for detecting the direction of the magnetic flux from the multi-pole segment magnets, the multipole segment magnet rotating direction of the magnet rotor a plurality of magnetic poles arranged along, the magnetic sensor includes a fixed layer in which a plurality of spin-valve, giant-magnetoresistive devices (magnetization direction is fixed, the magnetization direction rotates depending on the direction of the magnetic flux having a sensitive surface having a) a free layer, the feeling magnetized surface is intersects the magnetic flux, orthogonal to the magnitude of the amplitude between the magnetic flux density component are different to in the sense of magnetized surface, the magnetic sensor is positioned relative to said magnet rotor angle detection device.