To improve a brushless motor with a core which is compact, light weight and thin, and can prevent slipping off of a rotor sufficiently and realize good rotation accuracy.

A radial caps type brushless motor with a core A comprises a rotor 14 which fixes an annular magnet 2 to the inner circumference side of a rotor yoke 1 and one end 3a of a shaft 3 in the center of rotation, a bearing part 6 which supports the other end 3b of the shaft 3 fixed in a magnetic plate 7 in order to be freely rotatable and plurality of salient pole cores 3 which are placed in the circumference of the bearings part 6 and shoot out in the radial direction. The ring magnet 2 is magnetized to have the first magnetic pole with 2m (m is an integer larger than 1) in the inner surface facing the salient pole cores and the second magnetic pole with 2n (n is an integer larger than 1) in the surface facing the magnetic plate 7 and is placed close to the magnetic plate 7.