Position detection device

A position detection device comprising:

• a movable part which is movable in an X-axis direction and a Y-axis direction which are orthogonal to each other;
• a magnet which is movable integrally with the movable part;
• and
• a magnetic field detector which detects a magnetic field of the magnet, wherein the magnet includes a magnetic field detection surface which is a surface having a shape including two X-axis-direction sides parallel with each other along the X-axis direction, two Y-axis-direction sides parallel with each other along the Y-axis direction, and four connection sides each shaped as an arc or a line to connect respective end portions of the X-axis-direction sides and respective end portions of the Y-axis-direction sides,
• wherein the magnetic field detection surface is line-symmetric with respect to a line parallel with the X-axis direction and line-symmetric with respect to a line parallel with the Y-axis direction, and
• wherein the magnetic field detector is disposed to oppose the magnetic field detection surface and detects a component of the magnetic field of the magnet in the X-axis direction and a component of the magnetic field of the magnet in the Y-axis direction.