An abrasing apparatus includes an annular barrel having an upper opening The barrel is rotated around an exciting coil and is filled with magnetic abrasive powder which is arranged by magnetic flux generated by the exciting coil to form magnetic brush A work is embedded into the magnetic brush. The work is rotated together with a spindle and the barrel is rotated so that the surface of the work is abrased by the magnetic brush A bottom magnetic pole, a lateral magnetic pole and an upper magnetic pole are disposed in an inner periphery in the barrel in the promixity to the exciting coil and the strong magnetic brush is locally formed therein. The side portion of the work is located in the local magnetic brush, and the bottom, side and upper surfaces of the work are abrased like a mirror surface.