Provided is a two-component developer for developing an electrostatic latent image incorporating: toner particles each containing a toner mother particle having an external additive on a surface of the toner mother particle; and carrier particles each having a core material particle and a covering layer containing a resin on a surface of the core material particle, wherein the external additive contains inorganic particles; the inorganic particles are subjected to surface modification with silicone oil; a carbon content remained on a surface of the inorganic particle after the surface modification is within 3.0 to 10.0 mass %; a free carbon ratio on the surface of the inorganic particle is 70.0% or more; the carrier particles have a resistance in the range of 1.010.sup.9 to 5.010.sup.10 .Math.cm; and the resin in the covering layer contains a resin formed from a monomer containing an alicyclic methacrylic acid ester monomer.

A magnetic toner containing a magnetic toner particle having a binder resin and a magnetic body, and inorganic fine particles, wherein when the inorganic fine particles are classified as first inorganic fine particles, second inorganic fine particles, and third inorganic fine particles in accordance with fixing strength thereof to the magnetic toner particle and in the sequence of the weakness of the fixing strength, the content of the first inorganic fine particles, the ratio of the second inorganic fine particles to the first inorganic fine particles, and the coverage ratio X of coverage of the magnetic toner surface by the third inorganic fine particles are in prescribed ranges.

An electrostatic charge image developing carrier includes a magnetic particle and a coating resin layer that covers the magnetic particle and contains a silica particle, and a ratio of Si on a surface of the coating resin layer, determined by an X-ray photoelectron spectroscopy (XPS), is 6 atom % or more and 12 atom % or less.

A magnetic toner is provided that exhibits an excellent dot reproducibility and developing performance after being allowed to stand in a high temperature and high humidity environment and an excellent low-temperature fixability. The magnetic toner has an inorganic fine powder and a magnetic toner particle containing a binder resin, a magnetic body, and a release agent, wherein in a stress relaxation measurement using a rotating plate rheometer, the magnetic toner exhibits a yield value A at 25 C. of at least 310.sup.6 (sec), and the magnetic toner that has been heated to 80 C. and then cooled to 25 C. exhibits a yield value B at 25 C. of not more than 110.sup.5 (sec).

Provided are magnetic particles (cobalt ferrite) having a micrometer-order average particle diameter and similar particle diameters. A cobalt ferrite precursor is heated in the presence of a sulfite, thereby obtaining intended cobalt ferrite magnetic particles.

Magnetic particles (cobalt ferrite) having a micrometer-order average particle diameter and similar particle diameters. A cobalt ferrite precursor is heated in the presence of a sulfite, thereby obtaining intended cobalt ferrite magnetic particles.

A toner includes toner particles containing a binder resin. The binder resin contains an amorphous resin A and a crystalline polyester C. The amorphous resin A is a polyester and has, as a structure that forms a polyester backbone, (i) a polyethylene terephthalate structural moiety and (ii) a unit having a specified structure. An SP value of the amorphous resin A is represented by SP.sub.A, an SP value of the crystalline polyester C is represented by SP.sub.C, and a formula 1.00SP.sub.ASP.sub.C1.35 is satisfied. The toner contains a phosphorus element derived from a phosphorus compound, and a content of the phosphorus element in the toner based on a mass of the toner is 5 to 500 ppm.

Provided are cobalt ferrite particles having a micrometer-order average particle diameter and similar particle diameters. When a cobalt ferrite precursor is treated at a high temperature and a high pressure, an oxidation reaction is caused in the presence of a complexing agent, thereby obtaining intended cobalt ferrite magnetic particles.

Magnetic one-component toner has toner particles including: a toner base particle containing at least a binder resin and a magnetic powder, and an external additive attached to its surface. The toner base particle includes as a ferroelectric material a metal titanate and the dielectric constant of the toner base particle is 8.0 [F/m] or more but 12.0 [F/m] or less.