PURPOSE: To provide the manufacturing method, of a permanent magnet, which can ensure the matching property of the intensity of magnetic field at a permanent magnet used to constitute a magnetic sensor or the like to the sensitivity of a magnetic-to-electric conversion element and which can prevent an irregularity in an output from the magnetic-to-electric conversion element.

CONSTITUTION: The manufacturing method, of a permanent magnet, which is related to this invention is featured by the following: a magnetic-substance member 12 whose whole surface is covered with a resin film 13 is prepared and assembled in a product; and, after that, the magnetization treatment and the demagnetization treatment of said magnetic-substance member 12 are executed.