When a film is formed by using a sputter method, distribution variation due to a progress of target erosion generated during the film formation is suppressed, and film thickness distribution and resistance value distribution are corrected to an optimal state. In order to maintain the magnetic flux density formed on the target surface at a constant level, the distance between the target surface and the magnet surface (MT distance) is corrected in accordance with the progress of the target erosion. Further, two or more MT distances are set by a process recipe or the like while forming a thin film, and different distribution shapes are combined to form a near flat distribution shape.