To provide a small, low-cost and stable position detection magnetic sensor, using a small magnet suitable for consumer precision equipment.

The magnetic sensor 2 is placed on the small magnet 1, and a projecting magnetic material 3 is placed with a gap on top of the magnetic sensor. The magnetic material 3 is movable beyond the range of the horizontal dimension of the magnet 1 and magnetic sensor 2. A yoke 4, magnetically coupled with the magnetic material 3, is placed under the magnet 1. The projecting shape of the magnetic material 3 is steep around the center, leading to a gentle slope as going toward the edge. The displacement of the magnetic material 3 is calculated, by using the magnetic field detection output of magnetic detection parts at the center and both edges placed in the magnetic sensor 2.