The toner is a toner including a toner particle comprising a binder resin, a crystalline material, wherein, when a ratio of an area occupied by the crystalline material in a toner surface observed with a scanning electron microscope after ruthenium-staining the toner under a specific condition (1) is represented by S.sub.1 (%), a ratio of an area occupied by the crystalline material in the toner surface observed with the scanning electron microscope after ruthenium-staining the toner under a condition (2) is represented by S.sub.2 (%), and a dispersion diameter of a plurality of domains formed of the crystalline material on the toner surface observed with the scanning electron microscope after the ruthenium-staining the toner under the condition (2) is represented by R.sub.2 (nm), the following expressions (1), (2), and (3) are satisfied. $\begin{array}{cc}0.0S_{1}0.5& \left(1\right)\end{array}$$\begin{array}{cc}1.S_{2}10.& \left(2\right)\end{array}$$\begin{array}{cc}20R_{2}200& \left(3\right)\end{array}$

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 individually containing a binder resin and a coloring agent, and strontium titanate fine particles. The strontium titanate fine particles have a work function of 5.65 eV to 7.00 eV.

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.

An electrostatic charge image developing carrier includes magnetic particles and a resin coating layer that coats the magnetic particles, in which the resin coating layer contains inorganic particles, and in a case where an element ratio of metals and metalloids, that constitute the inorganic particles, is analyzed by X-ray photoelectron spectroscopy in a depth direction, and the element ratio at 0 seconds of etching is defined as A and the element ratio at 300 seconds of etching is defined as B, a value of BA is 0.5 atm % or more and 3.0 atm % or less.