Position detection device for an astride riding type vehicle

The present invention relates to a position detection device having a first member and a second member which are displaceable relative to each other, the first member comprising a magnet, and the second member comprising, in a range of a magnetic field of the magnet, a first Hall effect sensor for detecting a change in a property of the magnetic field, wherein a plate thickness of the magnet at its end face in a direction of a relative displacement of the first and second members is reduced.