the non magnetizing portion can endure the pressing force of making the permanent magnet and reduce the cost thereof accordingly the motor can be made having low torque ripple and high performance referring to fig9 the non magnetizing portion 2 is formed by cutting from the outer peripheral portion of the permanent magnet namely the non magnetizing portion is made in such a manner that h 2 gt h 1 where the width of the inner peripheral portion of the non magnetizing portion is h 1 and the width of the outer peripheral portion thereof is h 2 by forming the non magnetizing portion as explained above the cost of the material of the permanent magnet can be reduced when the high performance magnet is used and the weight of the motor can be reduced the shape of the non magnetizing portion can be made with high accuracy by pressing the high performance magnet especially smco magnet is made by the process of pressurizing and packing the powder of the material of the permanent magnet the higher the performance the permanent magnet is to have the greater the pressurizing force applied to the powder material of the permanent magnet is demanded when the permanent magnet is produced when the non magnetizing portion is formed as explained above the stress applied to the manufacturing tool is reduced compared with that of a non magnetizing portion in which the shape thereof is in an acute angle according to the present invention uniform pressuring force is applied to the permanent.