A development magnet roller for use in a development roller of an electrophotographic image forming apparatus is provided. The development magnet roller has a development pole to form a magnetic field causing a developer born on a surface of the development roller including the development magnet roller to rise in a form of a series of ears in a development area of the image forming apparatus where the development roller opposes an image bearing member, and in a magnetic flux density distribution in a normal line direction of the development pole, a peak magnetic flux density is 120 mT or greater, a zero gauss region width is 70° or greater, and a half-value region width is 40° or smaller.