PURPOSE: To obtain the dispersion stability for grains and to substantially remove viscosity from the grains by a method wherein magnetic grains are held in a crosslinking structure consisting of a hydrophilic polymer and the like together with a liquid dispersion medium.

CONSTITUTION: A magnetic granule consists of a crosslinking structural substance, a liquid dispersion medium and magnetic grains, and it has no viscosity substantially. The average grain diameter of the magnetic grains is 1W100μm. The arithmetic mean grain diameter obtained by d=Σnidi/Σni using an electron microscope photographing method and the like is used as the average grain diameter of the magnetic grains. Provided that it is the grain diameter of ni= grain diameter di. As the crosslinking structure, the water-soluble polymer such as guar gum, polyvinyl alcohol and the like, for example, is used as the desirable substance. As a result, the dispersion stability for the element can be obtained, and the viscosity of the magnetic granule can be removed substantially.