A magnetic detection unit includes: a first magnet configured to generate a first magnetic field; a second magnet arranged in parallel with the first magnet, the second magnet being configured to generate a second magnetic field in a direction opposite to a direction of the first magnetic field; and a hall element having a magnetic-flux detection surface, the hall element being configured to output a signal corresponding to a magnetic flux density passing through the magnetic-flux detection surface. The hall element is arranged at a position where a direction of a magnetic flux in a synthetic magnetic field of the first magnetic field and the second magnetic field is parallel to the magnetic-flux detection surface.