PURPOSE: To obtain a carrier superior in image characteristics and long in life, by specifying proportions of the components of ferrite consisting of MgO, Al2O3, Fe2O3, and ZnO, its electromagnetic characteristics, its particle diameter, and its surface state.

CONSTITUTION: This ferrite consists of 1W40mol% MgO, 1W40mol% Al2O3, 45W75mol% Fe2O3, and 0.1W30mol% ZnO, and it has 104W1012 ohmcm electric resistance, 15W80emu/g saturation magnetization value, ≤10 Oe coercive force Hc, ≥10 magnetic permeability μ, ≥50°C Curie temp. Tc, and 5W500μm average particle diameter. It is spherical, and the surface of each particle is oxidized or coated with resin. A sample was prepared and tested in actual copying. As a result, 70,000W100,000 sharp copies were obtained with this carrier, as compared with 50,000 copies obtained with the conventional ferrite carrier.